Great video, thanks for sharing it. It's amazing to see how the motorcycle manufacturers continued to hand-assemble machines 50 years after automobiles had adopted assembly lines for efficiency.
It reminds me of the videos of the BSA factory from roughly the same period, showing a very manual process. It's easy to see how Honda, with its modern casting technology and assembly line automation, was able to overtake the British.
BSA Factory Tour Part 1
BSA Factory Tour Part 2
BSA Factory Tour Part 3
BSA Factory Tour Part 4