George, total absense of perspiration - I've done a lot worse.

Homebrewer, disagree. If the engines are used in a marginally dusty environment you can grind the pistons away in a pretty short time. You will note Edwin is in central Texas. Dusty air is a way of life. That's why I suggested the intake filters.

Regards piston refit: I've used the pipe cutter trick, never found it lasted too long. The whack with a punch is a new one. I have heard of "Cooking" the piston to make it "Grow," don't know how hot or how long. Seems I've seen it in one forum or another, but don't remember where. I have always replaced them when the rest of the engine was still good. AND, I prefer ringed engines except for flat out speed.

Whether new or rebuilt, make your twin go full tilt.

Bill.