I think the first idea may work, but if it doesn't come loose it may be either seized real hard, or it could be a lower end problem. You didn't mention if it had been locked up while running, or if it just sat around a while. It seems to me the the 110 had a removable cylinder head, which would tell you if you removed the head it if was siezed in the upper part or lower. If the piston is all the way to the top it might be difficult to tell.
For engines, we freeze the bearings, and heat the cases, so the bearings slide right in.
With a cylinder head loose you might be able to heat the assembly in an oven or with a torch, then after it is hot, take it out and apply ice or dry ice to the piston top. Be sure to drain and flush all fluids first with some brake cleaner, let if thoroughly dry, and don't use a good oven.
Maybe even just pouring the dry ice on the center of the piston would work, as the parts should expand at different rates, especially if the cylinder is cast iron. Be sure to wear insulated gloves.
I tried using a hammer, wood and oil on and old atc when I was a kid, and ended up breaking the piston. My suggestion if you use that method is to get a 4x4 and cut it (cut the corners off) so it just fits in the cylinder to spread the force of the blow out. most hardware stores should be able to supply you with one cut this way.
One guy I talked to at the shop today said he once poured oil in the cylinder and used an impact wrench on the axle nut to spin the axle with the engine out of gear, then popped the clutch, but I'm not sure if this would work or cause more damage than you already have. I would think this could break loose a slightly stuck engine, but would cause damage if used on one stuck good.
Anyway good luck.