One would certainly think that there is a very nice shaped stock to be whittled out of that monstrosity. It would hold a desire to be as a scoped rifle.

Gibbs markings never detract

:):)

Always a chance of a "sleeving" but I would think it the original. On "military" ones the rear sight sleeve butts up to this "step". Gibbs could well have brought in the barreled actions as x54mm and rechambered to the .256 magnum ???

Here is a picture (thou not so good) of a Westley Richards M1900 with the similar step in contour.