Well you have created a monster judging by the number of posts
L39A1 S/n UE69 A 426
L42A1 D75 (original s.n L32431)

Of course there is one you won't be able to trace. A L39A1 clone done by Ms. Parker of A.J. Parker. Looks just like the government model except it's not marked as such. (much nicer condition as well) since it's had less than 100 rounds through it.

Bought that years before the Brits released the real ones because I thought they never would.