Once in a while someone re-posts the link to the film made by Mullard about valve manufacture. It seems Western Electric made something similar back in 1940 and I hadn't seen a link to it on this forum before. So if you're interested here it is
https://www.youtube.com/watch?v=_-JzxX75oYc. I see the person who posted it on Youtube says there may be a longer version too. Perhaps a search through the AT&T Archives would turn that up ?
I did search the forum as well as I conveniently could and I couldn't find an earlier link to this film here. But if I've missed it Mods then apologies - in that case feel free simply to delete this one.
Cheers,
GJ