SWAMPSCOTT – Red Rock Bistro owner Martin Bloom said he isn?t concerned over a possible demolition penalty fine from the Historical Commission because the restaurant was “a piece of junk.”Bloom, who bought the building with partners Robert Hoffman and Wellington Augusto last year, said they didn?t intend to completely demolish the building in the design of their new, bigger restaurant.?We didn?t have any idea the building was in as bad a shape when we got in there,” said Bloom Thursday. “We would have designed a much different building.”The total demolition in April was a surprise to the Historical Commission and the Zoning Board of Appeals, who had only approved partial demolition and extensive renovation. The owners are due to appear before the board to amend their permit on May 21.Building Inspector Rich Baldacci ordered a halt to the project May 9.On Tuesday the commission held a closed session to discuss its options for penalizing Red Rock owners for tearing down any historical portions of the building older than 75 years. Baldacci, who was at that meeting, reported that the commission must adhere to town bylaws and follow the process to determine if parts of the restaurant were historically significant. If the building is found to be historical, the owners could face a fine up to 10 percent of the building or property?s value. Patriot Properties assesses the property value to be $1,219,000, meaning a fine up to $121,900.Baldacci said he couldn?t estimate how long the process would take, since the incident is the first of its kind in Swampscott.Bloom was confident that Red Rock was not historically significant, claiming passion and experience in restoring his three other restaurants, most recently the Rosebud Diner in Davis Square. “That?s a historical landmark ? Red Rock doesn?t have any of that, this building was a wreck.”Bloom said his team?s building permits showed that “most of the building was redone in 1976,” and the most recent structure was composed of several alterations made since.