I'll be glad to share the engine problems .
The .100's valve guide adjustments have been maxed out. The tolerances are too wide from normal running time and need replacing. It also needs a basic going over from the pros.
The .72 took a pretty bad hit during a crash. I replaced the intake gasket and a few seals,, but it has developed some leaks and is blowing air/fuel around the fuel intake block.
Both engines have plenty of compression and straight rods and prop shafts. So maybe it won't be that bad of a bill $.

Thanks again for the info.