I visited Harry Quinn in Liverpool when I was learning to build frames in England in 1975. The most fascinating detail he provided was how fast he could make a frame. When I was there he said he was making his 2nd one that day. He did have a helper. While the speed is super impressive, it also means he didn't take extra time fussing with details. They have a workmanlike quality to them. At Ellis Briggs where I was, Andrew the journeyman builder and myself would take the better part of week making one.
His father started a frame business in 1890. Harry had a couple of older brothers that had a separate frame building business in Liverpool. His oldest one said he started when he was 13 before WWI. I wished I had asked them more questions.