The last time I was in the library at the Leeds Armouries I found this document in a box file along with a report on US duplex ammunition.
I’ve been collecting militaria of varying sorts for longer than I care to remember but one rule I’ve always applied is to be extremely wary of anything marked with SS runes. In this case I have absolutely no knowledge on the subject so I hand judgement over to those that have, should they wish to pass comment.
One thing I will ask. Is there any significance to two of the cases having only one flash-hole whilst the other has two?
Happy collecting, Peter