[flyingfrizzle]

This may help, acidtone is just a thinner in this case and any oil that is thinned down will penetrate into a rusted area better possibly. You could probably thin down some of the other oils and make them thinner to get better penetration. I think if you tried the can stuff now with no luck you will be pressed to get this to work. Best thing to do is fill that sucker up with some penetrate oil and (thinned or not) and let it sit for a few days to get it time to adsorb into the stuck areas. You may need to pull the heads and fill each cylinder with the oil and use a wooden block on each piston and try to knock them down. That or split the case and knock each piston out one by one then hone them back if they are not too far gone already. Good luck, thin down some oil and let it soak for some time and see what happens. You never know?