The Roving Reporter sent through a link to this video on YouTube, which looks like it was filmed some time in the 80s or so. The cooper who is the subject of the video is unlikely to still be alive today, and sadly I doubt he ever did find someone to pass his knowledge onto.
He works with no nails, no glue. As he says in the video, if he has to use a nail, he simply throws the item away. Another little gem from the video “It’s pretty complicated. If you don’t just get it right, you just done no good”
Just how much skilled knowledge have we really lost over the past 50 years? Be very very few people left that could work like that these days, yet once would have been commonplace. He makes all his own tools except for a saw and a brace & bit.
If you look at the pieces of timber he started with, the end result is a masterpiece. And it would still be holding water better than anything produced commerically these days.