The subject of 'bring back' items is enormous. War Trophy records are hard to find but all Allies did this and many members have contributed on where Govt donations have ended up from schools town halls legions etc. If members wish to add detail on this here then great as it sits nicely under 'captured equipment'.
You seem to be forgetting John 'Barney' Hines - probably the most proficient Australian 'collector' of German memorabilia.
Here we see him surrounded by German equipment he looted during the Battle of Polygon Wood in September 1917. He is counting money stolen from German POWs, wearing a German Army field cap and sitting amidst German weapons and personal equipment.
Here's one for you. Also, do you know if the photo in post #6 was taken at Bertangles Chateau? Just thinking as I know it was the Aussie HQ in 1918 and also that they displayed captured weapons there. Also, interesting to see the Colt M1895 "Potato Digger" in the foreground of the photo in post #16.