Phil, I did buy mine from Restoration Specialties.
Roger, the lower door windlace is a piece of cake (especially compared to putting the stuff in the track.) It's held on by the steel strip and a bunch of screws like Dan describes. That steel strip also extends over the windlace around the opening to secure that to the floor.
Recruit anyone you can to help with getting the windlace in the track. I don't think it's possible single handed. I know that I tried by myself.
