Just catching up with this thread now, i went looking for it as i'm currently doing a full resto on a Superman as well at the moment. The cabinet/backbox on this one i'm doing has also been a big pain the the arse but for different reasons, badly lifting/delaminating ply everywhere you look
It really was in horrible shape, i almost wondered at one point if a new can should've been built. I ended up resorting to removing layers of the top ply on some of the cab/backbox (some of it practically fell off)! and gluing in new ply. Turned out pretty sweet, finished the basecoat yesterday. Will start a resto thread when i get time!
Looking forward to further updates on this one you're doing Nino
