Hi Solothurn,
Welcome to the forum. All Erfurt lugers are military. I think this may possibly be an all matching Erfurt that has had the date scrubbed and the Ki/1933 added. The Ki supposedly stands for Kadette Institute. There is a DWM with the same stamp on the James Julia auction site. The desciption states that the stamp was recently added.
http://jamesdjulia.com/auctions/div_....asp?pageREQ=1
(Lot #1122)