Man, that really sucks. I had an interference problem with the 36W I built too. A shield covering a row of electrolytics on the top side smacked the speaker frame when I tried to install the chassis. I was able to fab a slightly different shield on my small metal brake and solve the problem, but it was a real close call. Considering how difficult it can be to plan for things like this in advance, I'm surprised I ever get anything finished. Hope this works out OK for you.