Nitro:
I understand all of this but the MA/MR/R - I think.
I see MI/MA/R, ME/MA/R, and similar notations in mine, but it's in the "Cost" column. My understanding is that this is a "cost/make profit" code. I think I remember reading somewhere that U of G can decipher this. I've never paid any attention to it.
Still curious about the R. B.T.B. 7th Gun entered in the description column.
I'm sure there's an obvious explanation, but I don't have a clue. Sorry.
15 of the 24 guns were finished by W&S, and all have an entry in the "Barrel or Maker's No" column. On my gun this # can by found on the bottom of the barrels.
If you look in the Webley & Scott serial number table in Brown, the date for that number should match the date in the A&N record. That number is a way of dating what are clearly identifiable W & S models retailed by makers that no records survive for.