HK33 Case?

I recently purchased another HK91 . It came with a bunch of accessories in a really nice wooden case. Behind the padding in the upper part of the case I found a test target that is in German and marked HK33 . Was this the original case for this gun? I am going to try to include pictures.

The case has some drilled blocks that the 22 conversion barrel slides through? Not sure what that was intended for.