Ok, so my uncle has had this Mark II for quite some years. Well recently, it has been only firing one round, then none at all. I spent 4 hours workin on it, to no avail. I have noticed that the pin that holds the bolt catch, the safety, and the hammer in place ALWAYS comes loose. The hammer strut seems to be somewhat stuck off to the side, and this thing is really tight we you try to get it all back together. I think I need to order a new pin and hammer strut. Any suggestions?