In combat , or in general ? In combat , A - frame with accoutrements . In general , on the move , most of their personal equipment would have been stowed on vehicles or pack animals .
Yes , I think it would be fine to wear a late war rucksack . I'm no expert on the SS , but I think a lot of them were pretty well motorised , certainly those in the West right at the beginning of the Normandy campaign . By Falaise it was a different matter...