And then there was two....
I visited a well known UKMilsurps Gunsmith yesterday and after a bit of looking, he came up with this!
Its been in his position a very long time indeed.....
This one lacks its mount, B.L 63, mine is B.L 33.
Its looking very much like a limited trails batch, the question is, of how many, logic dictates 100 examples, seems like a sensible number considering the tooling up costs of such an endeavour.