Jay,
Idea #1: Jeff Easter used to work at Holiday Motorhomes in Fife and later, Beaver Coach Sales. Before that it was Tweton's. He was the salesman that helped BJ and I. I recently talked to him and he now works at Tacoma RV in Fife. He may be able to tell you where the techs from Holiday Motor Homes are working.
Idea #2: Northwest Camping Center sprung up in Fife as the other were closing down. They have lots of what appears to be consignment inventory and every appearance of a shop. It may be were some of the techs went from Great American RV, the Monaco dealer and Holiday.
Idea #3: Paul Evert's has been recently mentioned as a star Navistar/Monaco dealer. I've driven by their lot in Fife a couple of times. There may be someone there with some knowledge of Monaco products.
Idea #4: When Wally Kimble and I drove our wives to Newfoundland he had about the same coach as you. He had a the same bedroom slide malfunction. We took it apart from the inside and found a bolt that had worked loose. It may be as simple as that.
Idea #5: Blue painters masking tape will seal most anything for a few hours and peals off easily. Drive it to Bend.
Idea #6: Call BCS and ask them where to take it in the SeaTac area.
Good luck!