Grigg if you can no longer get the pistons measure pin height pin size and check for any offset, check ring size and placement, skirt design and length. You may even send one off to some one like TRW or Keith Black there may be a close enough piston from something else that will work fine.
You may even find that there are options that no one has thought of yet like a hypereutectic piston. If you can’t get something off the shelf you could always have them made.
