Wolf Trap Farm Park got some unusual emergency aid yesterday. In a contest among demolition companies for the job of tearing down the fire-destroyed Filene Center, bids ranged from $28,400 to $705,705, until an Alexandria firm offered to do the job for free--and even pay $1,001 for the privilege.

The proposal, made by sealed bid in a room full of wrecking company executives at National Park Service Headquarters, was immediately accepted by the park service, which owns and operates Wolf Trap.

The company, Wrecking Corporation of America, also said it would sell salvaged bits of the theater as mementos, donating the proceeds to the Wolf Trap Foundation.

Wrecking Corp. president Michael P. Amman, 33, a McLean resident and music lover who often attended Wolf Trap concerts, said demolition work could start as early as tomorrow on the structure that burned down April 4.

The bid was one of 17 opened by the park service. Contract administrator Helen Staten presided over the session. In a bit of unplanned drama, Wrecking Corp.'s bid was the next to last she opened.

When Staten announced the bid, about a dozen representatives of competing wrecking companies burst into applause. But one competitor, Chuck Sloane, president of United Rigging & Hauling Inc.--which bid $63,999 for the job--muttered, "You're stupid," to Wrecking Corp. vice president Cranson Gates. Sloane said later that he was joking.

"He was the only honest man in the room," Gates chuckled.

"I've never seen anything like this," said Staten, who has worked for the park service for 15 years. "This is the first time in my experience where a contractor is actually paying the government to get work. It was quite a shock."

"We put our bid together this morning," Amman said. "I've been a Wolf Trap member for a couple of years, and I happened to get a flyer today, talking about a 'Wolf Trap Day' to raise money. I just wanted to help get things going so they can rebuild the center."

Amman, whose company tears down buildings nationwide, added, "This is probably a terrible thing to say, but because of my business, I've sat in that theater more than once, looked up at the ceiling, and wondered how to take the building down. Unfortunately, now it looks like I'll get the chance."

The Wolf Trap Foundation was taken by surprise. "Obviously, we're pleased," said John Robertson, a Wolf Trap board member who has been supervising the effort to build a temporary structure before the season opens June 15. "The guy is really giving a very heavy donation for Wolf Trap."