In years past i've rebuild snowmobile and bike motors. When replacing rings/pistons I used a 3 stone tool and kerosene to cross hatch the cylinder.
Do you guys do this to these small motors and if so, with what?

Edit,

Also, as you make changes and try out different mods after reassembly, do you use new gaskets each time or coat the old ones?
Can you just coat the head gasket for testing purposes?