Hi Stoney
You should not have to cut the crank, or at least I would not start there. Have you determined what is stuck on the engine, or is it just one mass of rust?
As you have already figured out, not being able to turn the engine over to get at all of the bolts, does kind of convert the engine into a Chinese Puzzle box of what to remove what to get at what.
Have you tried all the normal tricks of penetrating solutions in the cylinders?
If that didn't work then you are down to figuring out which parts of the engine are going to useable and which are going to be hardest to replace.
Remove the head and side cover inspect the block for signs of freeze damage it is cracked game over. Take a look at
http://canadianmilitarypattern.com/EngineTesting.htm bottom of page for major crack area.
If the crank looks like it might be good or machinable you can remove the crank and flywheel assembly as a unit by removing the connecting rod caps and bearing caps, remove the engine front cover pull the cam gear off the crank. With that removed you should be able to turn the cam shaft to get at the two screws that hold the cam shaft in place. Remove the cam with the cam out you can remove the engine front plate.
With the engine front plate gone and all the bearings caps and lower connecting caps removed you should be able to lift the crank and flywheel out. I would use a hoist so that you can pull the crank straight up.
OK guys what did I for get?
Hope this helps
Cheers Phil