1938 S/4 Luger question

[BILLG128]

Hi,
I recently bought a 1938 S/4 luger. I disassembled it and all the serial numbers matched however one grip is marked S and the other grip is marked with what looks like an R. Can someone tell me if they think these are repros or if they are correct. If they are repro grips does it affect the value much?
Any help would be appreciated.
TIA
Bill

[Rescue190]

I am assuming you meant to say S/42 Luger. Pics of the other side of the grips would also help.
John