ok I am stripping it down to the base parts looking for numbers and so far I have found a few
On the Bayonet lug there are the letters "SU" the thing that the gas piston pushes back has the numbers D-71618-- stamped on it along with the letters SG right beneath
right near the hammer spring it also says "enland"
so far that is all I have on it
EDIT: also the piece where the receiver slides into the stock is marked RIA or R1A