L39A1 used a L42 base clone ?

[Roger Payne]

I would concur with the above two gentlemen. The L39A1 may not be anywhere near as collectable as a L42A1, or even an Enforcer, but it has a value in its own right, both monetarily & historically. But once you start drilling holes in it that shouldn't be there, you've made it totally undesirable to anyone, save for at rock bottom prices.
A reasonable compromise would be to fit a 'no gunsmithing' mount as Brian suggests. Then at least you can easily change it back to its original state again, should you come to sell it in the future.

ATB