I have two Polish made 80% Ak receivers for sale. These are for building 5.56 or 5.45 firearms. Overall in very good condition. Both receivers have one internal rail that is discolored. I don’t believe it is rust as I’ve tried cleaning it off and it doesn’t come off. It is also smooth to the touch which is why I believe it is a discoloration and not rust. $60ea shipped. PayPal, Venmo and postal money order accepted. Tracking always provided.