I picked up at auction a .22 cal Benjamin model 312 pump up Air Rifle with no s/n. They started putting s/n on then about 1957. My research on the net – It was only 1540 of them made and now there are not many left in existence. This is an all brass rifle. If anyone knows were I can get a air valve kit. If you have a air valve tool for it that you would sale let me know. a exploded parts pic would be good also. Any information you can give me on this rebuild would be nice.