@Red Leg
It is my understanding that the claw mounts were added in the mid 1950’s in the UK. As you know, the WR mounts were difficult to make and faded out in the late 1930’s, and the H&H mounts were quite costly. I have several guns that had scopes added in the 50’s and the German claw mount seemed to be the direction most chose in that time period.
JJ is a good friend, he lives a little over an hour from me, he currently has a Maharajah engraved 425 WR that is the finest 425 in my collection. It has an octagon bbl (original from the factory)