Hey Brian,
The short length of the tunic is very common on the Austrian uniform, I can not find any refference that shows the pouch, it is not hung from his belt, but from a leather strap over his shoulder much like the cartridge pouches worn by Artillerists and some officers. The inner chin strap is show on page 125 of "The Emperor's new Coat" I have a copy because I swiped it from Joe when we visited a few years back, originally, I just borrowed it, but since I have not returned it, I guess I swiped it. Joe is going to have to come and get it him self. These helmets are discribed in "Good Soldier Scvejk" as he walke to the front when he misses his train.
Best wihses
Gus