I was given a Crosman 760, photos attached. I’m trying to find the year of it (I can see 818037 in very small font on the upper left side of the trigger assembly), and need to order parts for it - once I know which year it is!). Also got it partially dissembled but can’t see how the spring shown loose in the photo should go back in - I assume it should hold the pall into the firing mechanism until it is released by the trigger. Also, what holds the safety “piston” in place in front of the trigger - have I lost something?? Any help would be much appreciated!