In the early 80's I worked as a machinist at PNSY, Philadelphia Naval Ship Yard. In the building adjacent to the machine shop was the Boat Shop (wooden Boats and Sails) and also the Copper Smith. I loved to watch him work. His methods were very similar to what was shown on the video. He told me at one time during the war (WWII) there were as many as half a dozen Copper Smiths working. Alas, he was the last and he retired before I left PNSY.
I watched him make a copper bottle that would hold the bottle of champagne that would be used to christen a ship. It was perforated with stars.