1916 Erfurt - seeking info

[mtucker81]

Hi all,
I was recently given a 1916 Erfurt Luger by my father. He told me that my grandfather brought it back from Germany in 1918 when he went over with the Merchant Marines. A German man was waving it and asking for $1 American dollar in exchange for the luger and my grandfather felt sorry for him and gave him $5 for it. The gun has completely matching numbers except the bottom of the magazine. I can tell where something was stamped there once upon a time but I can not make out that it is a 94 for certain. There is also a code stamped into the front of the handle under the trigger that I have not been able to find any information on at all. Can anyone shed some light on what this code means as well as some of the other various stamps all over the gun that I have included pictures of? I have fired it quite a few times already and it shoots beautifully and is just as accurate as my M&P .45. Also, What would an approximate value be based on the previous information and pictures that I have included? Any other information that anyone can give is greatly appreciated as well. Thank you so much for any information you can provide and I am very happy to be a part of the luger owning community.