just purchsed 3 eton txl50 for my kids for xmas. 1 of them only has 80lbs of compression. possible to get away with just doing rings and a hone on the cyinders to get the compression back up. its very hard to get started but once running seems to run decent.

 

If you insist on not doing a bore/piston to make it 100% correct, I'd at least get a new piston.
Doing it right should only be 50-60 bucks more.
I've never been a "rings only" guy. New rings on a wore piston and cylinder. Never made sence to me.