At first blush, it looked like the caper to end all capers.

In full color and nearly as big as life, the 1,000-year-old Crown of St. Stephen - legendary symbol of Hungarian nationhood - shone from the pages of Time magazine.

And there it was again, radiating from the pages of The New York Times, The Washington Post and scores of relic that was hidden from the advancing Soviet Army in 1945 and stored for three decades in Fort Knox, Ky., until its controversial return to Budapest nine days ago.

But is it the real Crown of St. Stephen that has been returned to the Hungarian Communist government amidst pomp and ceremony, along with bitter denunciations from Hungarian refugees who viewed the gesture as bestowing legitimacy on a government they refuse to recognize?

Not so, if the widely published photographs depict the same relic that the U.S. government took to Budapest under extraordinary security arrangements.

Those pictures we've been looking at for the last month, it seems aren't the real McCoy.

Eleanor Perenyi the widow of a Hungarian baron whose father-in-law once served as the Imperial guardian of the Byzantine crown recognized the discrepencies almost immediately.

Gone was the roughly-cut Baroque sapphire atop a triangular enamel ornament on the front of the Holy Crown which, according to legend, was sent to Istvan, the first king of Hungary, late in the year 1000 by Pope Sylvester II.

Missing also was an irregularly-shaped almadine garnet atop a curved enamel plaque depicting Christ seated on a throne. It had been replaced by a nearly perfectly shaped semi-precious stone.

A halo around the head of Christ had one ray too many, and strands of pearls encircling the base of the crown seemed too perfect, not to mention that the numbers varied between photographs.

"It's very peculiar. It couldn't be the real crown. You can see that for yourself," said Mrs. Perenyi, a baroness by marriage, in an interview in her Stonington home.

During a visit to Budapest in 1937 with her mother, Grace Stone, Mrs. Perenyi met and married Baron Zsigmond Perenyi Jr., who father, Baron Zsigmond, was interior secretary of Hungary and honorary guardian of the crown. Mrs. Perenyi, who uses the title baroness socially, lived in Hungary until 1940 and subsequently was divorced.

She has written several books, including a biography of Franz Liszt and an autobiographical account of Hungary, "More was Lost." Her mother, writing under the name of Ethel Vance, wrote a popular pre-war anti-Nazi novel, "Escape," and other books.

Mrs. Perenyi and her mother have in their home a photograph of the baron holding the crown in 1938 on one of the rare occasions it was removed from the palace vault for display.

They also have reproductions of close-up photographs from the Hungarian National Archives, which Mrs. Perenyi said raised some serious questions in her mind about thea uthenticity of the crown that has been returned to Budapest.

The questions raised by the baroness seemed to lead only to a conspiracy of deceit that would cause an international uproar.

"I don't think those are the same objects. How do we know the real cans at the end of the war? How do some prominent art historians, how we know we are returning the true crown was turned over to the America seemed answer the questions. And they categorially confirmed the authenticity of the crown that was returned.

"Oh, the Time (magazine) picture. That's only a replica," said Victor Covey, chief of a conservation at the National Gallery of Art.

Covey helped care for the crown while it was in U.S. custody and traveled to Budapest for its ceremonial transfer to Hungary. Along with Thomas Gerth, a State Department desk officer, he had a baroque American pearl installed on the crown to fill a gap, after first receiving permission from the Hungarians.

Another Crown of St. Stephen exemeritus of the Art Museum of Princeton, also said he recognized the Time photograph as that of one of several replicas displayed in various countries. Kelleher is scheduled to lecture on the crown at the gallery today.

The Vatican in Rome has one that was crafted by Hungarian artisans in the late 19th century and sent to Rome as a gift to the church, he said. The Hungarians have at least one more, and another a said to be in Germany, Kelleher added.

"When you look closely at the enamel and the stones, you begin to realize at once that it has to be a replica," Kelleher said of the Time magazine picture.

The same is true, he said, of a widely published black-and-white photograph transmitted to hundreds of newspapers by United Press International.

The captions of both pictures identified the relic picture as the crown of St. Stephen.

Kelleher's observation caused some flurry of research yesterday at both Time and UPI, where photo editors sought to authenticate their pictures.

Marvin Zim, a spokesman for Time, said one of the magazine's photographers hung around Fort Knox for three days hoping to photograph the crown just before its departure, only to be denied permission by the State Department.

Zim said the magazine then contacted a Springfield, Va., woman whose Hungarian-born mother was said to have had a color photograph of the real Crown of St. Stephen. The magazine borrowed that picture and used in its Jan. 9 issue.

The Springfield woman, Cecilia Bros, who was active in the protest against returning the crown to Budapest, said in a telephone interview, however, she didn't know if her photograph was authentic or not.

"I told Time I didn't think any color pictures of the crown had ever been taken. I have no idea if it's a replica," Mrs. Bros said.

Zim, however, wasn't ready to concede Time had used the wrong picture.

"We have the picture of the crown when it was presented (in Budapest). It looks accurate to us. It's conceivable that the picture we used is of a replica, but at this point we're not convinced it is inaccurate," he said.

UPI said its picture was a file photo the news agency obtained in September, 1965, from either the State Department or the U.S. Information Agency.

All of the official explanations didn't seem to impress Mrs. Perenyi.

"I'm beginning to have even blacker suspicions about this whole thing. What are all these replicas doing floating around the world?" asked Mrs. Perenyi, adding she has no quarrel with returning the crown to the Hungarians, as long as she knows exactly what it is that has been returned.

"My father-in-law could have buried that hing, for all I know. The Americans might not have recovered the right crown. How are we supposed to ever know what really was returned?" she asked.

"I may be getting my wind up over nothing, but this all strikes me as rather stange. I wish I could talk to my father-in-law in his grave. He'd know," she said.