It's the sear spring come off or the rear grip screw. I've serviced thousands of spyders and this happens alllllllllllll the time.
Etek 3LT grey/black f/s
Valken Proton greyish/black f/s
68 4500 PE stubby, LP output f/s
68 4500 AIR tank(no reg) f/s
Creed Battery, eyes and noid f/s