S/42 Matching Luger ???

[Lugerdoc]

Dean, It would be helpful if you could make out the 4 letters on the left side of the breech block, but probably from a nazi depo rework or replacement part, as is the s/42 marking on the barrel. According to Costanzo's "WOL Proofmarks" your GW3 translates to Gewehr Waffenwerke Kornbusch & Co. who was doing luger reworks in 1934-35. TH