It will interesting to see how this engine come out.........but..........engines that are not stuck after sitting for years often ( not always) are not stuck because when they were running they were consuming large amounts of oil. The excessive oil helps present the rust. So when they do run after very long time sitting they make really good mosquito foggers.
Assume during your Initial testing and observations you tried to determine if the cooling system was ok.........no external cracked blocks, head or missing or damaged freeze plugs, water pumps turns like is should.
Good luck keep us updated.
