OK,I have more info, on the barrels ahead of the flats I had said there was a H with a crown, that turns out to be a BP with a crown.
I looked in Diggory Hadoke's book, which is an excellent book and identified the symbols as Birmingham proof marks between 1954 and 1989.
So I would say these are replacement barrels and are faily current. So how does that affect my asking price? I have two questions though,
Why didn't they chamber it for 2 3/4"? If they were made after 1950 I would assume that they would have done that.
Also would Atkin Grant and Lang been involved and were they incorperated with them at that time?

Mike Proctor