Hi all, Thank you for your replies, much appreciated. The mystery deepens. I haven't got the gun to hand yet.Like I said, long story to do with importation laws, etc. The photos were sent by the gun store to me yesterday. I'm just waiting for my gun licence to be delivered, then I will take possession of it. It is a 2 1/2 hour drive away, and we are still in lockdown here. Once I have it I will examine it in more detail, and log the extra information on this site. The flaming bomb and ordinance wheel stamps are on the plate, just worn a little, as well as the inspectors' initials "RLB". I live in Ireland. The gun came from the collection of my late friend Ralph B White. He lived in Silver Lake, LA. He had a military background, Force Recon, was a marksman and knew his guns, so he would have known the history of these. I had no idea about the provenance of this one.I just liked the look of it when I was offered one at long distance by his family. Here are some more images from the store. The barrels are clearly stamped Field Grade.