The only two guns on the OP's list that are surplus are the Mosin and the Swiss rifle. So while he may regret selling the listed firearms, most are just modern guns that can be fairly easily replaced.
My main rule of gun collecting is to never sell anything. As for the surplus/C&R thing, yes it has to be at least 50 years old to qualify as a C&R, but military surplus is just that, former military guns or accouterments.
Some are easy to identify and others are maybe not so easy. I have a couple of examples, to wit:
A Galil ARM that I built from a cut up rifle. The receiver is aftermarket, but the rest of the rifle is 100% Israeli surplus. Technically it is a new, modern rifle, but all the components, less the receiver are military surplus.
Another one is a 1958 Polish PMK AK47. This one is from another kit and has all the original 1958 parts except the barrel. The receiver is the original receiver that has been welded back together and modified to eliminate the third pin. As defined by the ATF, it now has a new receiver and is no longer a machine gun. Is it C&R? Surplus? Or merely a new rifle. for me it is kind of tough to call.
