THERE IS a partial skull, including a few teeth, somewhere in Mexico City that a lot of people in five countries would give much to see. It may or may not be the last mortal remnant of Argentine financier David Graiver, who may or may not have died in a fiery plane crash north of Acapulco in 1976.

If he did die, and the evidence is mounting that he did, then the Argentine terrorist Montoneros are out about $17 million they allegedly gave him to invest for them. If Graiver is dead, then assorted small investors in Argentina, Mexico and God knows where else, many of them impoverished, have no hope of recovering several millions more.

If Graiver died in the crash, various financial watchdogs and courts in Buenos Aires, New York, Brussels, Geneva and Mexico City will have to slog through a labyrinth of banking shenanigans that might involve as much as $200 million without any testimony from the one man who understood it all.

And if Graiver is gone, his family has a better chance of one day getting out of jail in Argentina.

If, however, Graiver was not killed in the crash, then most of these issues remain unsettled. There is no public evidence that he is alive. The difficulty is that the only people who claim to have proof will not say what that proof is, except in closed court.

However, at least one judge has been convinced that criminal indictments against Graiver should not yet be dropped.

"It is our position that he is still alive, yes," said Martin Marcus, assistant district attorney of New York County. "Some of the evidence, because it was presented to a grand jury, is bound [secret] by law. Other evidence relates to what we know of Graiver's present whereabouts."

Judge Arnold Fraiman listened to Marcus reveal that evidence behind closed doors and refused in July to dismiss a 90-page indictment against Graiver for vast "misappropriation of money, funds and property" in New York County's Superior Court. Trial for the other four big money men indicted begins in January.

Much is expected to emerge at that trial about the way Graiver and his friends allegedly took over and then gutted the American Bank and Trust Co. of New York. The bank, the indictment said, was the foundation of Graiver's financial house of cards, funneling millions in bogus loans to dummy corporations set up in Graiver's name. Hundreds of trusting investors, lulled by Graiver's playboy charm and his glamorous and repectable friends, put money into those firms that went right into Graiver's pockets.

The Argentine government maintains that if Graiver is alive, much of the looted money belongs to the people of Argentina. Graiver's wife, father and brother are in prison on charges related to the military government's claim that Graiver handled $17 million for the terrorist Montonero organization, money the guerrillas got as ransom in various kidnapings over the years.

The plots and subplots go on forever, throwing off questions like radioactive particles: Did Graiver help the guerrillas willingly or under threats against his family? Did the guerrilla money finance Graiver's takeover of AB & T, or was it the other way around. Graiver funneling AB&T money to them? What financial links are there, if any, to other terrorist groups with known representatives in Mexico? And just where does the Graiver connection lead in the web of interlocking directorates that is the world banking community?

The most intriguing question, the one that could shed light on all the others, is whether David Graiver still lives. It just seems almost too perfect, to have crashed in a blaze of publicity a few days before his financial empire began to crumble. The patness of it all has been a powerful spur to speculation; the complexity of Graiver's web has led many to think he was just too smart to die in such a simple way. Yet the evidence seems overwhelming that David Graiver is dead.

At 35, Graiver was a burly, energetic scene-stealer, equally accustomed to giving orders and to thoroughly charming anyone in the room. He was a family man who yet dazzled his associates by running his affairs largely out of a computer like memory. He seldom wrote anything down.

He was accustomed to taking weekend trips from the plush life he led in New York to the family holdings in Mexico City. Partly it was for tax purposes that he spent a lot of time out of the United States; partly it was business.

THE FIRST WEEKEND in August 1976, he chartered a $10,000 private flight to Mexico City from Republic Air Charter, an executive service then run by a moonlighting Pan American pilot named Robert Meyer. It was pretty short notice, and Meyer said he told Graiver an Eastern Airlines flight for $200 would reach Mexico City only an hour after the charter would. Graiver took the charter. "I was used to dealing with people who had more money than sense," Meyer said. The trip, he recalled, was uneventful. Graiver returned to New York by commercial jet.

The following Friday evening, Aug. 6, Graiver chartered a jet from another firm, Hansa Jet Corp. of Fort Lauderdale (since changed to Walkers Cay Air Terminal). His personal chauffeur took him to LaGuardia Airport and put him on the plane, getting a bearhug of farewell from his effusive boss. Graiver, the only passenger on the nine-passenger craft, cheerfully introduced himself to the pilot and copilot. La Guardia records showed that pilot Michael Bann had filed the customary flight plan for the journey: LaGuardia to New Orleans for refueling and then on to Acapulco.

There was a long line of planes waiting to take off at La Guardia, however, and by the time the twin-engine Falcon was airborne, Bann and his copilot decided they would have to refuel short of New Orleans. The plane went to Memphis and then to Houston for another refill.

Bann called a local friend in Houston before the plane landed, and the friend came to the airport to see him. The two sat chatting in the friend's car outside Houston's executive air terminal, idly noting that Graiver entered the terminal and used the telephone several times.

Graiver then got back on the airplane for the final leg of the trip to Acapulco.

At 2:40 a.m. on Saturday, Aug. 7, the gleaming white jet crashed at full speed into the north face of the mountain called Cerro El Burro, 40 miles north of Acapulco.

About three hours later, Ed Chandler of Hansa Jet, an exFBI agent, got a call in Florida that the plane was overdue at Acapulco. He knew, he said, that the plane must have crashed, and immediately took off for Mexico. So it was that Chandler was at the armory building in Chilpancingo Saturday night, looking at three trays of "brown meat, like a barbecue" that used to be three human beings.

The area is dotted with very poor villages whose inhabitants know the mountains well. It took a Mexican rescue team four hours to reach the apparently had explored it well. There had been a fire from the crash, but papers and notebooks were scattered about when rescue workers arrived.

Chandler was there when Graiver's father, Juan, himself a financial wizard, and his brother, Isidoro, arrived to identify the body. "Isidoro saw a piece of cloth that could have been a shirt of his borther's, but it was hard to link one body to it . . . there was a part of a torso and Isidoro said the family 'had decided,' in those words, that the torso was David's," Chandler recalled.

At the local funeral home, undertaker Luis Ramon Romero told Somos magazine of Argentina some months later that under the conditions, "I couldn't have orcognized my own son . . . They told me they recognized the shirt and the hair on the chest [of the torso]," he continued. "There were only three hands, a hairy piece of skin, an intestine and that part of a trunk . . . the rest had to be put in three bags, only because it was certain that three persons had been on the plane."

Graiver's family, distraught enough to win an Oscar if they were acting, Chandler said, ordered David's body cremated in spite of their Jewish faith. Chandler arranged for the presumed bodies of the two pilots to be returned to their homes and went back to Florida.

Three days later, he said, he was notified that another bag or remains had been picked up from the hillside. Rather to bury it with appropriate dignity in the local cemetery at Chilpancingo.

It is a partial skull from that bag of body parts that Robert Meyer thinks may be the skull of David Graiver.

An "Obsessed" Investigator

MEYER, by his own admission, is "obsessed, consumed" with the David Graiver case. He initially got involved in an effort to collect the $10,000 Graiver owed him for the trip to Mexico City the first weekend in August, but he cheerfully admits he has spent far more than that in trying to uncover what he says is "just the tip of the iceberg" of Graiver's full story.

Meyer has been to the mountain crash site twice. The first time, in October 1976, three months after the wreck, he went to look for the flight and voice recorders, the "black box" designed to withstand crashes, that Mexican authorities had said could not be found at the scene. He was unsuccessful.

The second time, in January 1977, he spent a week in a nearby village, displaying samples of what he wanted to the local residents and buying anything from the wreck. He got leather notebook covers, briefcases, papers and, finally, two sections of the 5-inch-wide strip of heavy aluminum foil that is the flight recorder tape. "Then this guy walked in with the voice recorder tape wound around a stick," Meyer recalled. "I felt smug about that." He paid $5 for the two tapes.

He also managed somehow, he said, to get a look at the contents of the buried sack of body parts. At this point the story gets fuzzy. There are reports that Meyer tried unsuccessfully to mail a skull to the United States, but he won't discuss them.

"The FBI says the Mexican government has it; ask them," Meyer said. The FBI denies ever having examined or ordered examined any kind of skull or jaw fragment for the purposes of identifying David Graiver, and the Mexican government has no comment.

Sources close to the U.S. investigation, however, said that the Mexican authorities reported that Meyer's find was the skull of a child and therefore unrelated to the Graiver case. "I saw it and it's not the skull of a child," Meyer insisted. He asserted that the fragment includes a few teeth, enough for a positives identification.

Meanwhile, the tapes have been read and listened to by experts at the National Transportation Safety Board, but they reveal little about the causes of the Graiver crash. The flight recorder tape was useless, a 43-foot segment apparently torn from the part of the tape feeding into the recorder mechanism rather than from the part already recorded.

The voice recorder tape, according to NTSB audio section head Paul C. Turner, was "very poor quality" but contained no cockpit conversation on the track reserved for that. There was only the voice of the pilot. Bann, repeatedly trying to contact Acapulco for instructions and apparently getting no response.

"If the guy was in trouble before the crash, he didn't sound particularly concerned," Turner said. "He just got down too low too early."

The terse five-page Mexico government report on the accident, available at the NTSB, says the cause of the crash was pilot error. Bann, it says, told Acapulco ground control he was 35 miles short of the runway when actually he was 75 miles out. The plane began a descent from 14,000 feet much earlier than it should have and crashed into Cerro El Burro at 7,000 feet. Just before the crash, in the period covered by the tape, the plane would have been blocked by the mountain from any radio contact with Acapulco.

Questions remain about the final moments of the flight, but they do not bear directly on the question of whether David Graiver is alive. The Mexican investigation was "very superficial," according to a federal police official who was there at the time of the crash. The Mexico air traffic controller tapes have allegedly been erased, and the Mexican government did not invite the American NTSB to take part in the probe. There was no official reason why the Mexicans should have do so, since the plane was French-made and the crash occurred in Mexico, but those who are suspicious tend for these reasons to be more so.

Chandler would like Graiver to be alive because Ghandler's air firm is being sued for $30 million in a wrongful death action by Graiver's family. Meyer wants Graiver alive in order to get his $10,000 back. The FBI would like him living to tell what he knows about the banking tangle. Mexican authorities would like Graiver to talk about terrorists.

All of these people, however, are convinced that Graiver was the passenger who boarded the Falcon in New York; that he remained on the plane in Houston; and that the plane crashed quite innocently into the mountain and was not bombed out of the air. The FBI continues to investigate rumors that Graiver was seen in Miami, in Czechoslovakia and elsewhere, but none has panned out yet.

This is all known to the district attorney of New York County, who must appear in court again Jan. 8 to present Judge Fraiman any further evidence he has that Gravier is alive and that the indictments against him should not be dismissed. It will be interesting to hear what he says.