to be honest mate , i think before you do too much damage it might be time to do a restore or just an engine rebuild ? by the sound of it seems maybe too much movement in rings '
for the cost of a rebuild (if no piston needed) just rings bearings and a few gaskets maybe$30 /40 depends on where the bits come from , online here is a good place to begin though , in the store . they ask all the right questions too oh yeh , and top n bottom seals too while your at it , not a hard job and the pleasure you will get out if it is a great feeling
and i bet as soon as you see the base engineless the bug will bite

Dave