Wow. A lot of work, and it’s real stuff, not packed with CG.
Oh, and the producer didn’t charge anything for his time. (Although I’m sure that his company charged whatever time his employees put into it.)
The work was funded by the government of England. They told the producer “There is all this footage in the archives, and we want you to do something special with it for the 100th anniversary of the end of the war. Will you accept?”
“So I accepted - and didn’t even know what we had. And it had to be something special. I couldn’t just use the same ten clips that everyone else has used for every WW I documentary”.
It took them something like 100 hours to figure out how to process a minute of old film into black and white so it had the proper speed, the right lighting, getting rid of the imperfections, etc. They didn’t even know if it could be done.
(Okay - I’m off my soap box!)