Evening Peter, its the so called ASAS Bitch/Break rifle that I will try to re-create, all seem to be a bit different, some with short barrels, some more modestly converted with simple cut back FE's, pistol grips added to the forend and L2A1 selectors/short pistol grip trigger plungers to allow full auto plus the straight 30rd magazine..

Add a camo paint job and bobs your uncle... A question you might be able to answer Peter, do you know what weapon camo colours were used in general at that time?