I recently purchased an Ithaca Model 72 saddle gun. It has a screw missing. Holding the rifle with the barrel to the right and looking at the receiver there are two screws on each end of the receiver. I'm missing the one closest to the forearm. Where can I get one and what do I ask for? The rifle�s action when you lever it seems anaemic for lack of a better term. It also doesn�t eject 22 shells but I believe it has it�s ejector. Were they problematic rifles? .