I looked even harder and still nothing. I found this gem
, but it's only 7 minutes long, silent with music, and all the prompt cards are Deustch. So far he was the only person interested enough in the process to make a film about the actual production of a piece of photographic equipment.
You would think there is at least a "How Things Work" video that's aired on Discovery or something, but I am even having trouble finding that. Would love to see something in this area!
Edit: Just realized that video I linked only includes footage of the Leica 1 being built starting at about 6:34.