OK I tried but can't seem to get a picture good enough. I can fax someone a drawing of what I saw on the flats but in the mean time I will try to describe.
On the barrel flats,
729, a crown over letters BNP, 12 inside a turned square,
2 1/2", 3 tons per squire inch.
Just ahead of the flats is what appears to be an H with a crown over it.Also on one side is a X with the letters P/I with a crown on oppisite side of the X.
Now on the reciever it is stamped BNP, it also has a slash with a crown on top.
Sorry I am not an expert with a digital camera. If I can figure out what to do then I will take some photos. My barrel flats does not have the same as #1, I do not recall a screw in the front lug.And does not have a number on the rear lug. So what can you make of it from my description?

Mike Proctor