Mike - agree with your comment about the rifle's 1906 date and nitro proof marks in effect then (post 1896 and post 1904 would dictate a nitro mark if proofed for nitro. I'm keeping this at nitro-for-black loadings.

Curly - I appreciate the help. I was planning on selling most of the vintage ammo, keeping some to go with each of the 360EX rifles I have now, so no plans to shoot it. Previous owner was nice enough to save an empty Kynoch box and 9 berdan cases (Kynoch and Eley) in addition to the loaded ammo. I will have to take the Daniel Fraser black powder ammo out of its bubble wrap soon and photograph that.

Re the rear trigger, appreciate the advice. I have not done anything except use the rifle and the trigger is no longer sticking. I still like the advice of cleaning off the trigger blade that's on this side of the trigger plate. I have Kroil on hand.

Apologies if I hadn't already posted flats and water table. Coming shortly, along with a range report. No barrel markings except as reported above: "Watson Bros" and "29 Old Bond Street London."