Another 1939/42 question

[litsnsirn]

I see from my searches that this is a fairly common model. I have one that is a "found in the attic" type deal from a friend at work and I am trying to determine a fair amount to offer him for it. Judging from a few clues, I am going to say that it is a wwII take home, mismatched mags, all numbered parts match(including internals, except grips, which I'll get into later), blueing is maybe 60-70% with the finish on the barrel being kind of splotchy(but it doesn't seem pitted) in some places but the barrel still looks sharp, and a somewhat worn but complete 1938 Frost Jahnel, Breslau holster with tool. One of my questions is what should the markings on the grips look like? The left grip is written(deep on the inside) with a name and Nov 4, 1945, it also has an "R" stamped and a mark that is sort of a square with rounded sides but is too light to make it out. The right grip has an "S" and what looks almost like a capital M split in the middle and spaced apart a little. Do these sound like replacements? And for the big big one, what's a fair value?