Re: Luger 9MM Identification Help Needed!!
Luger military pistols, with few exceptions, were stamped with the year of manufacture on the receiver ring. Police and commercial guns were not. The markings on your gun seem to be police markings, c. 1922. "S. Me. VII I.54" would mean Schutzpolizei* Merseburg, Seventh District, Station 1, Pistol number 54. "S.P. S .T." probably indicates Schutzpolizei Potsdam, but the "S.T." I don't know. Maybe someone else can help. The 2.66 would mean the same as the "1.54" in the other marking.
Those numbers are not month-year dates, but pistol numbers.
*Schutzpolizei literally means "protection police", the ordinary city cops, not the state police or the secret police.