Sorry mate, can't help you either much, as I went to school after 1945...
The first part is definitely german, most likely kurrent handwriting:
http://www.kurrent.de/_html/schreibschrift.htm
I can only decipher single words, the letter starts with "Es drängt mich Hr (Herr) z (zu) D...", basically Mr . D... urges the writer to do something.
The second part is (old?) greek, definitely no german.
Maybe you have luck at the axishistory form, there are some people who may be able to read it. Another forum in german is forum-der-wehrmacht.de, you may post there under "bilder und photos", though the board is more about history of ww2, but they are a friendly bunch of guys and many speak english there.