If your motor has suffered a catastrophic event its likely the crankshaft
is damaged as well. You wont know for sure till you get it off. It still
could just be stuck. I believe this is an A25 flywheel but is the same as
yours. Knowing what’s in there may help you plan your approach.
Tubs.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.