Abas Major and Webley Senior

Abas Major and Webley Senior 

With thanks to Steve. He says the Senior is contemporary with the Abas and was exported to the US just after WW2: 

[The Senior] is an early post-War contemporary with the Abas. This is one of the first Seniors made after the war: it retains the prewar trigger which they were still using up. The grips are one plain prewar and one marked Webley post war, again using what they still had in inventory. It has no serial number and has the early form of post war barrel knurling.

Chris Thrale, author of a forthcoming book about Webley pistols, explains:

As had been the practice with the Mark 1, a small batch of Senior's were assembled in 1940 to celebrate Webley's 150 year anniversary. (1790-1940) These pistols followed the same specification as their Mark 1 siblings in that they were assembled using some pre war components, which included the trigger, and one plain grip to the left side.
The serial numbering ceased, to be replaced by batch numbering, and the blued finish became somewhat glossier, a finish which continued after the war.