Chuck,
* Unsure of what kind of recorder you traded; but, on the surface, it looks like you got the best part of that deal.
* To fully and accurately evaluate/value your example, some pictures will be necessary. Please post some clear/near-up digitals of the overall (Lft, Rt, Top, Btm, Frt., Rear, )piece and of the markings(E/M, O.xxxx, K, S/42, etc)
* All you have described so far fits the description of a "K" Date Navy (E/M + O.xxxx)made by S/42 (code for Mauser @ Oberndorf, Germany). E/M was the Navy Inspector's acceptance stamp. O.xxxx is the grip strap marking indicating assignment to the
Marinestation der Ostsee. This was the Baltic Naval station headquartered @ Kiel. What are the "xxxx" numerals which follow the "O"??
* "K" was the code assigned for the year "1934". Germany was attempting a covert recovery from the ravages of unemployment. She was still under the restrictions of WWI's Versailles Treaty which prohibited her from rearming. The Allies were preoccupied with the Depression. Hitler won favor and power based on restoring Germany to prosperity. He viewed restoring the Military and associated employment as a prerequisite. Hence the covert action. Wasn't till early 1935 before Germany renounced the Treaty.
* Only a little under 11,000 "K" Dates were made overall. Of this, estimates of 300 are assigned to the "K" Date Navy variation. Only 17 examples have been reported per records I have seen.
* The barrel should actually be 100mm (3.936") as measured from the breech end of the chamber to the tip of the muzzle. This can be accurately confirmed by taking an
unloaded pistol, with the firing pin uncocked, and inserting a pencil(Eraser first) into the bore. When seated down onto the breech face, mark the pencil @ the muzzle, retract the pencil, and measure.
* Coupled with the excellent condition you report, this makes this example a wonderfull find if truely all original and all matching.
* The holster - likely came along at a later 1939-1940 date. Does this 1939 leather bear any additional markings you can detect?? A picture here of the marking can be revealing. Are the WaA numbers under the eagle readable?? The "SA" may represent a number of things. If the "A" & "S" are intertwined with the S dominant, look for the letter "L" ( same size as "A") as well. LSA was a leather maker - L.Schultz & Co., Augsburg.
* You report the mags are not matching. Please describe & report the S/N's, eagle acceptance marks, and materials used(unblued/blue tin body, wood/plastic/alum. base plug, etc.).
* While S/N 43 (no suffix) is possible, please confirm the entire S/N to include a small lower case alpha letter if present. This can be found on the front of the grip frame. Assuring an unloaded condition(Toggle locked back, Mag removed, chamber empty), the number and/or letter will appear on the vertical machined flat ahead of the trigger guard and beneath the barrel.
* Per your knowledge or opinion, has this piece ever been re-blued/restored/etc.?? Where does the wear occur?? Any pitting of the metal surface?? Here's where digitals/scans are worth a thousand words.
* Guess we can't peel this onion all at one time. I've given you a bunch of questions to consider. Be assured, the forum members and the Navy experts are looking forward to your continued reports of this exciting find. We'll reciprocate as data is offered.
Respectfully,
WR