This is an interesting Luger with a long history.  It is an Alphabet commercial made in 1927-1928 by DWM (Deutsche Waffen und Munitionsfabriken).  The barrel was likely originally a 98mm, .30 Luger.  It was replaced in a police rework with a 100mm, 9mm barrel and a sear safety was added at that time.  The mag bottom is stamped with an E/K.  The E/K indicates an acceptance by the police in the late 30's.  The E/K has been questioned as to originality.  You can also see the "2" on the mag bottom indicating the second mag. 

The grip strap is marked S.D.III.R.81 with the "R" "x"ed out.  The marking is a property of the Schutzpolizei in Dusseldorf, III Centurion.  The "R" was originally an indication of a precinct weapon but the "R" marking was dropped in 1932 so it was cancelled on this gun.  "81" means weapon number 81 for that police organization.  Notice the 5 pip "G" stamp and the odd looking eagle on the underside of the barrel.

The gun was likely captured in the Ruhr area of Germany.  See Jan Still's "Weimar Lugers", Page 138, Figure 37f.

$1950 + shipping.  SOLD