Spot welded and automotive panel adhesive as seam sealer. Which didn't quite end up 100% waterproof. The whole rear is getting re-done and tig welded soon because of that. The rear lower quarters were folded up if you look closely they are about 4 inches higher clearance than stock (they were rusty so it serves a dual purpose). The rear inside liner didn't have to be messed with at all, so those inner structural pinch seams are still intact.
-- Simon "I may be wrong, but I'm not uncertain." -- Robert A. Heinlein