If I had the OP`s cylinder here in my hands I could clean that one up in just a few mins, like Kevin I have cleaned many dozens of them up through the years and they ran for many more years on firewood duty. Just hand sanding that cylinder would not take much longer to get rid of the remaining transfer.and then we might end up with an out of round cyl. but if that thin, may be too worn topside. i wonder what the OP's exp is, but i see he is into an engine and it is apart... and appears to be no more damages from that...