There are a few pictures at this site
http://www.wheatcroftcollection.com/Sdkfz7.html
The rear drop down doors reveal tool racks and storage shelves.
The twin side doors open to reveal a large space which would hold
six whicker baskets each containing three shells making eighteen in total.
It looks like that another two rows of 6 baskets would fit on top of the
first row making a capacity of 54 shells.
Can anyone confirm this?
Im still waiting for the book on the 7 to arrive
Regards Stewart