1916 DWM valuation

[Anopsis]

Hello everyone,
I really hate to be the guy that posts on a forum for the first time with a "what's it worth" question, but I don't know where to go.
A friend has asked me to help him sell a Luger but I know nothing about them. I filled out the ident sheets and here's what I have so far:

Toggle Inscription: DWM
Chamber Inscription: 1916
Toggle Type: Squared and knurled
Grip Safety: Not Present
Stock Lug: Present
Caliber: 9mm
Grip Type: Checkered brown (material unknown), no insignia
Thumb Safety: Safe in rear position, GESICHERT visible when safe
Marks: Crown, Crown over M, Crown over M
All small parts & barrel marked "59". Rear toggle link stamped with 59 on rear, stamped 100 on top.
Witness marks are aligned and barrel is stamped with crown over M as well
Front sight stamped 1916
Extractor marked GELADEN
Barrel length: 5"
Magazine: wood bottom, appears to be marked 969 with "a" suffix.

Other items to note is that the grip screw on the left side is missing, and the wood base of the magazine has a chunk missing. It must have happened a long time ago since the break is smooth and worn.

Hope you guys can help!

Thanks,
Chad