Ian,
If you could master brazing and lead loading, the spirits of those old blokes in the video would be really proud of you!
It shows how the ES was virtually a hand-built car, probably why corrosion was able to get such a hold in some areas? Knowing Volvo, I can imagine that some of those jigs and pressings still exist in some dark corner of an old Swedish facory somewhere, I'm told CVI automotive may have acquired some, who knows?
https://www.cvi-automotive.se/en