The attached red-lined drawing shows the proposed solution to the Top Mass interference issue, labeled 1) in my previous report. It is a small hog-out of (the adjacent) one of the two Top Mass upper plates. This obviously requires some dis-assembly, but appears to be the simplest and quickest solution. By wrapping the part in foil and milling it in a vise, it can be done with minimal contamination using alcohol as a cutting fluid and careful handling. Then we could possibly get clearance to clean it up in the lab and re-install.