Damn.... I was hoping you had a piston for that bad boy too. I have that same kit with a malossi 70cc head with plug for the decomp hole..... Same thing, blew a hole right threw the piston and marked up the cylinder the same way. The scuffs you can barely even feel so I can't imagine it would do anything ill to a new piston. Looks exactly like yours. Seems like those heads would be better if the hole was just welded shut with aluminum and then smoothed out on the inside.