Took the 377 out of the stock and used a flat screw driver to lift the plastic off each end of that pin. Same thing getting it back on. That pin goes thru part of the trigger but I still think the main trigger assembly and main spring are held in by those two screws on the bottom.When you tapped out the pin with the wood dowl did there seem to be pressure against it? Is your wooden dowl inside the receiver and not holding the trigger in?There is a little pin with e-clips to remove the safety levers. There's not much you can do to that single blade trigger. If you had an old Mendoza parts gun you could get a dual blade trigger which is better. Can't do anything to it either but you don't need to.The 377 ia a smaller gun but the receiver is the same diameter as the bigger guns, just shorter. If you look at the writing on the gun it might have made for Crosman. You may already know this. Mine does as well as my RM577. also they both have blue and white spacers between the recoil pad and stock. Mendoza Mendoza's just have white. The little machine gun stamped by the writing is one Mendoza was famous for back in the day.I shot the 377 and 577. I think the scope on the 377 is broke. Switch scopes tomorrow. The 577 was tack driving as well as the RM600 yesterday. The Mendoza made TF M12 scope might be broke also.