The video title is clickbait, and the guy claiming this is Ansel's Adams' camera is just having a laugh. There must be tens of thousands of A Adams in the world and he has no other evidence. Would be worth a fortune at auction if it were. One of the YouTube comments is that the repair company Ace seen on the label around 3:20 was in New Orleans (I don't know USA phone number allocations but perhaps someone else can confirm that), which is a long way from AA's San Francisco base. Anyway, I understood that AA used an Olympus for 35mm, because in his memoirs (or some other writing) he complained that his OM4 instruction manual did not explain spot metering adequately.
He may well have used a Pentax Spotmeter V but I believe he later used the digital spotmeter. If he did not then I must have sold mine under false pretences because I advertised it as "
As used by Ansel Adams!"