[ImperialCrown]

Welcome to Allpar. Possibly rusted cylinder walls? This could be exacerbated by a damp environment. Proper storage would have been a shot of motor oil in each spark plug hole before sitting.
A boroscope (auto parts store tool loan?) could take a look through the spark plg hole.

 

[ImperialCrown]

Is it possible that a valve is stuck rusted open? This could stop a piston as it approached TDC in either direction.

 

[ImperialCrown]

If a torque converter bolt has backed itself out, it can hit the back of the block.