Jerry/Don,
Finding photos of wartime leather shops is something, I must admit, I've never searched for. (strange, since I collect photos of pistols/holsters being worn) That would be neat to find.
Jerry as for your questions about the depots making holsters, why wouldn't they?
The various Waffen-Werk depots were of various sizes, and each depot was generally assigned to work on specific items. (ie- Firearms, wheeled vehicles, tanks, field gear, footwear, artillery pieces, and so on.....)
A depot that was equipped to repair leather items, such as holsters, boots, ammo pouches, saddles, would have all the tools and equipment needed to make a holster as well. So, all they would really need is new hides supplied, which again, I'm sure they had since they needed new hides to perform many of the repairs as well.
As I mentioned earlier, rework holsters are a different subject matter. They are much more common and easy to find. Strangely many collectors don't value them as much, so often they can be obtained much cheaper than a standard holster.
Some depot reworks were marked with the depot proof mark that did the work. Others were not. I've attached a few holsters here that are all marked.
So not to confuse readers, these photos are all depot reworked holsters. The photos I posted above are depot produced holsters.
Matt