My Gebirgsjaeger were originally bought to provide a late war German force for the eastern front in order to avoid painting the camouflage smocks that I would need for a contemporaneous company of Heer troops. See the gallery under Vpered Na Berlin or Battle for Liberation.
Here, that late war force has been adapted and expanded to allow for troops that formed part of the German army that invaded Poland in September 1939. The main changes are really to strip away all the later war equipment (Kettenkrads, Maultiers, StuGs etc) and really go back to basics.