http://www.e-gunparts.com/productsch...rModel=1570zG3
http://www.robertrtg.com/g3.html
Most of the screws, bolts, pins, ect. can be used from a original Real Steel HKG3. The top two sites are pretty good the second being used more recently by my dad to build a TM G3 similar to the one issued to him in the Bundeswehr. Exept for the receiver(which is a CA metal body), barrel(CA metal again), and obvious airsoft internals its 95% the real deal.