Need help on a Erfurt 1918

[luscioman]

This is my first Luger and I need some help on it. Sorry I dont have all my pics to post on this with me. The rest are in the office so I can add them later. I just picked this up last week from someone that said it didnt work. I took it apart and the the firing pin was not seated. No problem. However I have been searching the site to figure out the markings on this and havent figured much out. I know that it was a 1918 by the date on the top. However the slide has some markings that I have not been able to match. The entire top half has matching numbers and the frame is different.