Time For a rebuild
Ok here's what i'm thinking / guessing , those spool type mounts don't have much give so if theres a slight inaccuracy of the placement of the front mounts it could easily put you of that half inch way back at the trans mount.
I think I would try loosening the front mounts at the engine block then see if you can get the rear mount to line up , if it does you may need to do some tweaking on the front mounts , elongate holes , shims whatever.