Perhaps they were friends — the older sailor who walked with a limp and always had a pipe clenched in his teeth, and the younger salt with the busted nose and the beat-up, mismatched shoes.

If not comrades in life, they became so in death, drowning together in the iron tomb of the USS Monitor as it capsized off Cape Hatteras in 1862 and sank upside down in 40 fathoms of water.

Over a century later, their skeletons would be found, one atop the other — the younger man still with his shoes on — amid the guns, equipment and debris inside the famous ship’s turret.

And Tuesday, a few months shy of 150 years since their faces were last seen in the midst of the Civil War, likenesses of the noble Yankee seamen were unveiled at the Navy Memorial in downtown Washington.

Experts have used plaster models of the sailors’ skulls to create facial reconstructions that could provide clues to their identities.

The unveiling is the culmination of almost 40 years of research into the Monitor shipwreck by the National Oceanic and Atmospheric Administration, the Navy, the Mariners’ Museum in Newport News, Va., and many other groups.

“I think it’s pretty amazing that we’ve finally gotten here,” said John D. Broadwater, a retired NOAA archaeologist who has been studying the Monitor for decades. “We can look into the eyes of those two men. It’s a little bit eerie, and kind of moving.”

“It’s really pretty impressive that we’ve got the technology to do that,” he said last week. “Beyond all that, it’s just very emotional for me.”

Broadwater, who dove on the Monitor wreck and this month published a book about it, was one of the first to begin excavating the human remains from inside the turret when it was raised from the bottom in 2002.

The Monitor is famous for battling the Confederate ship CSS Virginia, formerly the Merrimack, on March 9, 1862, in history’s first fight between ironclad warships — 150 years ago this Friday.

The battle, at Hampton Roads, was a draw, with each ship’s cannonballs bouncing off the other’s iron sides.

Later that year, the Virginia — which had been built out of the former USS Merrimack — was blown up to keep it out of the hands of Union soldiers. Little of it has ever been found.

The Monitor sank in a gale on Dec. 31, 1862. Most of the 63 crewmen escaped.

Sixteen men perished, but these two sets of remains are the only ones that have ever been recovered. The identities of all are known, and many crew members are depicted in old photographs — including a famous series taken on the ship by photographer James F. Gibson in July 1862.

Experts hope that the facial reconstructions might resemble one or two of the men in the pictures so historians might identify, or at least see the faces of, those who drowned in the turret.

Already, experts have noted a resemblance between the reconstructed face of the older sailor and that of the Monitor’s Welsh-born first-class fireman, Robert Williams, 30.

In two of Gibson’s pictures, officials said, Williams appears in a cap and mustache, as he stands with his arms folded. He is surrounded by other members of the crew, who lounge on the deck, playing checkers and smoking pipes.

“We just did a match up of the photo of Robert Williams with the older sailor’s facial reconstruction and it is very close,” James P. Delgado, director of NOAA’s Maritime Heritage Program, wrote in an e-mail Monday. “I wish I could Photoshop in the mustache and hat.”

“To see him in the group photo, standing on that deck, arms crossed ... is why we have tried to literally put a face to these guys and move them from the anonymity [where] death and time have placed them,” Delgado wrote.

One problem: Williams appears in the photos to be a strapping man, taller than many of his shipmates. But the older skeleton seems to be that of a runty fellow, about 5-foot-61 / 2, according to the military’s anthropological study of the remains.

The wreck of the Monitor was located in 1973 by a Duke University research ship about 16 miles off the North Carolina coast in the stormy and treacherous region called “the graveyard of the Atlantic.”

The two almost complete skeletons were found in the turret when it was hauled out of the water, and scientists and researchers have been studying them for almost a decade. Neither has been conclusively identified.

A few facts were gleaned from the examination of their remains: The younger man’s broken nose, for example, and indications of a possible limp in the older man, a ring on one of his fingers, and a groove in his front teeth where he bit down on his pipe.

In January, forensics experts at Louisiana State University began applying clay to the skull models, using skin thickness formulas to re-create the likenesses.

The work was done at the university’s Forensic Anthropology and Computer Enhancement Services, or FACES, laboratory, where scientists often use the process to help police identify unknown remains.

“It’s exciting, in a sense, to bring these people back to life,” Mary Manhein, the lab director, said of the Monitor project. “It would be even more exciting if they could find out who they are, if in some small way these people could be traced to their descendants. That would be a wonderful thing.”

Manhein said the lab has compiled data on facial skin thicknesses for people of different ages, sexes and population groups.

Forensic sculptors first glue the proper thickness markers, which are actually pencil erasers of varying heights, to some 40 locations on the skull.

Then they smooth on the clay at the proper thickness and contour to fill out the face, lab research associate Nicole Harris said.

Prosthetic eyes are inserted — always brown, she said, because most people have brown eyes. Upon completion, photos are often taken and the images are further enhanced.

The models the scientists used are based on the actual skulls, which are housed with the skeletons at a special military identification laboratory in Hawaii.

Now that almost a decade has passed since the remains were recovered, some NOAA experts believe that the current sesquicentennial of the Civil War is the time for the sailors to be buried at Arlington National Cemetery.

“Let’s put these two men to rest,” said David W. Alberg, superintendent of NOAA’s Monitor National Marine Sanctuary. They “belong to history and the nation, and it’s time that the nation honors them.”