valuation question

[JAMES]

I own a luger dated 1913 at the front of the receiver further noted "ERFURT" with a crown above it and a #26 adjacent. Looking at the pistol from the safety side, I find GESICHERT at or beneath the safety. The serial # is 4426, and all the parts seem to be consistantly numbered "26". The finish is chrome and the barrel length is 81mm. On the opposite side I am finding 3 small markings which all have crowns. From left to right the 1st has a crown with what looks like an old english B, a crown over a script looking D, and a crown over a C.


The holster is a blackish brown in good general condition with a good buckle and strap, a pull tab, an interior compartment for a cleaner and an exterior pouch containing an additional magazine.


I have never shot it, and I have no idea of its caliber.


My interest is valuation and rareity of what I am guessing is WW1 vintage. It was surrendered to my friend after the war in Bavaria by a very old man who may have been a policeman during the war.