ID of Dad's Luger - Year/Commerical?

[OldCuber]

Hi all,
I have inherited my Dad's Luger some years ago and it has been stored away for years. He bought it from some guy in PA before WWII. With renewed interest, I'm having trouble narrowing the year of manufacture and whether it is commercial. I recently broke it down for cleaning and here are the markings:

Script DWM on rear toggle link. No year on barrel or chamber; its blank.
Serial # 6522 with an "a" like character below, on the front Frame.
With the Receiver and Barrel removed, there is a "G" stamped on the inside of the Frame.
On the rear of the Frame is stamped "Made in Germany"
It has wood handles and wood on the only magazine.
It has the thumb safety.
All parts that I saw have the "22" matched stamp.

I guess that is the best I can do without pictures. I assume this is a commerical model?
I remember firing it with my Dad some years ago. Still have the 9mm ammo.

I guess for some reason I'm all of a sudden real interested in finding out all I can about this piece. The internet is the a great place to start!
Your help is appreciated...

Thanks,
Jim