Um if your close to the service limit you should get another cylinder or replate it. The hard chrome is only a couple of thousands thick. The A B C Vertex Pistons refer to their cylinder differences and what piston came with their barrel. A matched cylinder works barrel and piston could be a A B or C Vetex piston size new. I guess you could fit one of the Vertex Pistons in your cylinder. But you do need to have the size checked and get the proper fit of clearence between the two.