Found the driver and bits at a garage sale without a case. Looks like the original case wasn't very functional anyways…
This folding case holds the driver, 5 “holders”, and 20 bits. The bits are held in place with 4x2mm round magnets. Case itself is held shut using a friction fit latch.
The first few tines inserting/removing the driver, as well as opening/closing the lid may be a bit tight. Repeated use should loosen up the internal mechanisms.
The author hasn't provided the model origin yet.