I made the new end for the piston, but you can purchase them from Mac1 Airguns.... The quad rings are available from a good Hydraulics supply (or Mac1, or wwwscopesandammo.com).... To remove the roll pins, using a 1/16" dril, carefullyt drill through the opposite (blind) side of the forearm using the center of the roll pin for a guide.... Once you have a 1/16" hole, which is lined up with the center of the pin, use a 1/8" drill and come back from the blind side until you hit the roll pin.... Then using a 1/8" pin punch, drift the roll pin out through the original hole....

Bob