I have been fortunate several times. I traded a Franchi LAW-12, semi-auto combat shotgun for a mint 1943 BRNO 98k. I was generally bored with the Franchi as it is a pure combat weapon with no secondary use. You can't even plink as it will not cycle shooting low brass loads. My Mossberg 590 is more than adequate for home defense and far more flexible.
That Mauser has matching serials, laminate stock and near perfect bore. The owner threw in a bayonet, scabbard and frog as well. Few war issue Mausers are in better condition. It hasn't been fired in years and likely will never be fired again.
Another gem trade obtained by me is an Enfield No.4 Mk.1 in exchange for a Marlin 25MN, .22 mag bolt rifle. The Marlin had been re-stocked and received a trigger job. It was fitted with a 3x9 scope. It shot excellent groups and was nicely balanced and great for small game or even turkey where rifles are permitted.
A dealer saw the rifle at the range, tried it and loved it. He offered to trade if there was something he had that I might want. He wanted the Marlin for personal use. I suggested that he could build one himself for not much money, but he was not interested in taking the time and money to do so. I agreed to look at what he had. Two weeks later at his store, I saw the Enfield. It had just been delivered. This isn't your typical No.4 Mk1*, it was manufactured by Savage under Lend Lease contract to the US government. The receiver is stamped US PROPERTY. This was a mid-run rifle. It's overall condition was very good. Very minor wear of the bore. The two-groove rifling still has pretty sharp edges. The wood is almost completely free of dings and there are no cracks. As nice as this Enfield is, it still didn't have the value of the Marlin. So, the dealer also offered a Mosin-Nagant M1891/1930 which was in armory new condition. I thought that he must really be smitten with that Marlin, and I readily accepted. This became a range shooter, while the Enfield was retired. That same fellow still has that Marlin (16 years later, mind you) and he still enjoys it.
My regards,
Widewing