I liked and enjoyed the video . I would have also like to know what was real film footage vs just stock or recreation.

Spoiler alert:
Two details I did not hear mentioned I have always understood without confirmation, one, the forward bomb was encased in solid concrete in the ship, I suspect, to delay potential detection, protect it from gunfire on their approach, and after watching the movie, maybe help with proper ramming buoyancing and COG of the ship. Second detail might hare been expected propaganda, but supposedly a lot of German big shots were inspecting the ship after the "failed" mission, when it blew up, killing them as a mission bonus.

Yes, those Brits were tough, and I liked the out of the box thinking at the time valuing Grit, smarts, attitude, initiative over the typical at the time goal of first discipline and always by the book, set in their ways thinking.