The center window issue is an almost universal C-Dory problem if you open and close that window a lot over time. After "fixing" it several times by disassemblng, banging the brass washer and reassembling it, I decided it is badly engineered. Buying new parts isn't likely a longterm solution. In 2004 "Fairbro" mentioned drilling holes for pins. This is a reasonable solution, but I didn't want to drill holes in it. I find that propping the window with a stick works great. I have three stick lengths for different angles of open. BTW; much of the earlier discussion on this can't be accessed any more.