Your Mauser is a:
5th variation (military-finish with acceptance A/WaA135; approx. 32,000 pieces)
Characteristics

Legend:
Mauser barrel
Mauser-Werke A.G. Oberndorf a. N.
Mod. HSc -------- Kal 7,65 mm
Finish:
military-finish
Grips:
chequered walnut grips
Serial number:
6-digit number on front grip strap
3-digit number on barrel
3-digit number inside slide (electro-pencilled on front end)
Acceptance stamp:
E/WaA 135 on left trigger guard
Test proof stamp:
E/N right on trigger guard
E/N right on slide
E/N on barrel

Every Mauser HSc pistol produced during WWII will bear the factory firing proof (Beschuss-stempel) of an Eagle over “N” stamped on the right trigger guard web, on the front of the right slide and on the barrel breech block. Commercial pistols will have only these firing proofs. Pistols procured by a military or police organization will also have a specific acceptance proof stamped on the left rear trigger guard web. For example, Eagle over “655”, “135”, or “WaA135” for Army; Eagle over “L” or “F” for Police; and an Eagle over “M” on the front grip strap and later an Eagle over “MIII/8” on the left trigger guard web for the Navy.

Mauser-Werke began production at serial number 700001. All WWII produced Mauser HSc's were marked at the factory with the complete six-digit serial number on the lower front grip strap. In addition, the bottom of the barrel breech was stamped with the last three digits of the serial number and the same three digits were electro-penciled by hand under the muzzle of the slide. German production of the HSc ended in the closing days of the war, on April 19, 1945, the serial numbers having reached almost 952000. This represents about 252,000 HSc pistols manufactured during the Nazi regime in Germany.

I own a Mauser HSC serial number starting with 714
That one cost me 80 eurok's.

regards
Willem.
Netherlands.