Sculptor Frederick E. Hart, whose bronze grouping of three battle-weary soldiers forms part of the Vietnam Veterans Memorial, has collected $85,000 in royalties from sales of souvenir reproductions such as T-shirts, post cards and belt buckles, financial records show.

Hart, who was paid $330,000 for designing and executing the sculpture, obtained the royalties through a shared copyright he holds under an unusual arrangement that turned the work over to the U.S. government.

Hart and his lawyer, Susan Chaires, said he has spent most of the royalties on lawyers' fees to protect and enforce the copyright provisions, and that the arrangement prevents inappropriate or distasteful reproductions. "I really have seen very little money," Hart said.

Maya Ying Lin, the designer of the memorial's chief element, the black granite chevron-shaped wall bearing the names of those killed in Vietnam, receives no royalties and holds no copyright. "I don't like the idea of making a profit off those lives," said Lin, a New York artist and architect who received a $20,000 prize when her design was selected in a competition.

Hart's seven-foot bronze creation was added to the memorial in 1984 as a concession to a vocal group backed by then-secretary of the interior James G. Watt that opposed Lin's austere design as unheroic. Current Interior Secretary Donald P. Hodel said through a spokesman that he was unaware Hart was getting royalties. "He was surprised," the spokesman said.

American Legion spokesman John Hanson, whose organization raised $1.2 million for establishment of the memorial, said he found it hard to believe that "a national monument, which was given to the United States in a ceremony I attended, doesn't belong to the United States.

"It was always my assumption that once a memorial is put on national land, it's our memorial," he said. "That's the real irony of the thing."

Jan C. Scruggs, the Vietnam veteran who led the drive to build the memorial as president of the Vietnam Veterans Memorial Fund, said Hart promised to donate half his royalties to veterans' charities. "He does have himself a little oil well," Scruggs said. "It's not a gusher, but it's a nice, healthy, steady flow."

Financial statements of the memorial fund show it had received $170,611 in royalties on the sale of memorial items in the three years ending March 31, 1987. Half went to Hart, and half to the fund. Hart, in an interview, said he had offered to turn over his copyrights to the Disabled American Veterans organization, but "they weren't interested because it was too much trouble."

Jim Hall, associate national director of communications for the DAV, said the group had not rejected the offer. "We have been approached about it. We simply haven't made a decision on it at this point," he said.

Licensing agreements produce royalties on an array of products that carry depictions of the sculpture, including pictures, post cards, belt buckles, T-shirts and hats. In addition, agreement has recently been reached with the Franklin Mint for small reproduction statues, to sell for about $300 each.

Hart said his relationship with Scruggs and the veterans fund has been difficult and that he has threatened them with lawsuits over remarks about him. "Occasionally they go to the press and try to stick it to me," he said. Chaires, his lawyer, said Hart is entitled to royalties for 50 years past his death.

A similar royalty arrangement covers the "Lone Sailor" statue at the Navy memorial, the capital's newest monument. Sculptor Stanley Bleifeld has received $100,000 in royalties from the sale of small reproductions sold to raise money for the monument, said Adm. William Thompson, president of the U.S. Navy Memorial Foundation, which has not yet turned over its memorial to the government.

Thompson said the artist cited the example of the Vietnam memorial's arrangement in negotiating for copyrights.