If there is deep scoring , the cylinder will have to be welded , the plating is very thin. You can get in touch with Eric Gorr / Forward Motion ( link on the left ) and probably have the cylinder bored oversize 265 cc or so. Maybe he will even have a cylinder ready to go on the shelf. The pistons will be availiable at a cost similar to a standard piston. FM can bore , plate and port the cylinder to your needs , for far less money than most other people , and it can very well be the cheapest option.