It looks like you have a stock set off a Rifle No3 Mk1* (T) A. It is not off the 'common' P'14 sniper rifle that bears the Model 1918 scope on over bore claw mounts, but from one of the 421 rifles set up by Alex Martin in early WW2 using Great War rifles & Great War Aldis scopes (Aldis for the most part, a few other types of vintage WW1 scopes were also fitted).
I have an original No3 Mk1* (T) A rifle that has been fitted with a replacement stock as it had been sporterised, but the previous owner didn't make the best of jobs of it. If you decide you want to sell your stock I'd be very interested!