A puzzle, and one better suited for the guys who are well learned in the Leningrad Seige statistics! I recently located a set of trench art cups from an Axis soldier(Presumably German, but truthfully, no clue) He engraved these small cups with various dates and locations where he was located at, and I'm wondering if it is at all possible to attempt to figure out Approximately Which unit he may have been with? The locations are:

Demjansk Dezember 1942
Mga Juli 1943
Penna Marz 1942
Luga September 1943
Pleskau April 1944
Neva Ladoga See 1943

The Ladoga cup is not in the style of the other cups and is very difficult to make out due to corrosion from being ground dug(as are all these cups, but this one is abit worse than the others). For some unknown reason, there is a second identical cup for Luga.
So, how about it? Any ideas from the tactical troop location experts out there?