The case of Libuse Mazur's controversial sewing machine has finally closed, 2 1/2 years after her Reston neighbors told the 75-year-old Czech immigrant her Singer had to go.

The sewing machine won.

The loser was the Reston Home Owners Association, arbiter of changes great and small in the model community. The association left the Fairfax County Circuit Court with something of a lesson: housing covenants are not always carved in stone.

"Well, I guess it would be correct to say that the settlement we reached today was basically the same on that was discussed about a year ago," said association spokesman David Wells, as he explained why the group believed Mrs. Mazur's sewing business was such an affront to the neighborhood that it took her to court.

The sewing business, the home-owner board held, violated the association rules governing the use of residences and warranted bringing suit. "People move here because of the restrictions," Wells said.

Mrs. Mazur's son, an economics researcher, accepted the association's challenge. "The whole thing was such a peanut issue," said Mojmir Mazur, who shares the 3-bedroom town house on Insha Court with his mother. "My mother should receive a medal for wanting to work when she's this age. It keeps her alive."

"Maybe, if it had been a 19-year-old somebody else repairing shoes in the house next door, the decision might have been different," agreed Wells. "But what do you do when it's a 75-year-old immigrant old lady from Czechoslovakia? She's a pretty sympathic character."

This week, the board decided that maybe Mrs. Mazur's sympathetic persona was too formidable an opponent, and moments before Fairfax Circuit Court Judge Barnard Jennings was to rule in the case, agreed to allow her to continue with her $6,000-a-year business. There will be a few minor restrictions -- only half days on Saturday and no work past 7:30 p.m. on weekdays.

"It's what she was doing all along, anyway," said Mazur, speaking for his mother, whose English is minimal.

The controversy over the sewing business began 2 1/2 years ago when some of the neighbors on Insha Court complained to the Machaans Cluster, one of many homeowner groups operating as part of the Reston Home Owners, that Mazur's business was causing a parking problem and was in violation of the community's land covenants.

The covenants, a lengthy set of do's and don'ts filed with each homeowner's deed, broadly spell out what a resident may do with his property. One of those was a restriction supposedly limiting residences to home and "incidental" use. Mrs. Mazur argued that guidelines interpreting the covenants were approved after she began her business in January 1977 and that Fairfax County had approved her business through a grandfather clause to a zoning law. cThe homeowners' board did not agree and they sued Mrs. Mazur's son, who owns the home, in an effort to end her business.

When the issue went before Jennings this week, the board had a change of mind. After listening to testimony from some neighbors who had recorded the comings and goings of nearly every visitor to the Mazur home for two months -- including car color and license plate numbers, Judge Jennings told the parties that he believed Mrs. Mazur was performing a valuable service for the neighborhood. But the judge added that her work might be so successful that it was causing traffic problems. He asked the parties to reconsider settling.They did and the board gave in.

"All along, this whole thing was always a tribal-like issue," said Mzaur. "I can't believe that some people had nothing better to do than to hide behind their curtains for two months to see who was going into my mother's house.

"This is America?"