It's a homemade "key" for the luggage locks on the old Krauser hard bags. Proper key blanks seem to be hard to find for these old locks.
When examining the locks i realized they are very simple mechanisms. Even calling them locks is kind of a stretch. they are just tricky latches and are very easy to "pick". It took a few attempts to get the keys right but they work just fine.
The material is an old curtain bracket or something like that, 1.4mm thick.
Mark