[Lynn Eades]

Alex, I don't think the Scout was ever set up for anything else, other than the Boys (in the front)
Your Hotchkiss mount would be quite narrow compared to the Scout mount.
Also we (N.Z.) took on the Hotchkiss because we were short of LMGs.
They were as I recall surplus WWI guns.

The British carriers were built around specific guns, First the M.G. Carrier was built around the Vickers water cooled MMG.
This carrier was superseded by 3 carrier models;
The Bren, equipped in the front with, funnily enough a Bren gun. (about 1937- 1938) Originally built around the idea of the gun crew being dropped off and the driver retiring with his carrier.
The Scout was a fighting carrier equiped and built specifically for the Boys anti tank rifle, in the front and carried a Bren in the rear. (1939ish)
The third one being the AOP (an adaption of the Scout) No Boys, no Bren LMG, just personal arms.

The point being that the British built the carriers around current arms designs.