I think the unity coupled Mcintosh designs would be easier to wind than most people think, far easier than a Peerless or UTC or Freed top quality unit. But I don't think there's a market for them for two reasons, old Macs don't sound all that great, and most hobbyists are not experienced and persistent enough to make a Mc design work from scratch.

Any of two dozen wiring mistakes give you a power oscillator that will tear itself up unless carefully brought up on a current limited nench supply. Hobbyists today have no test equipment and little discipline to do things in an orderly fashion.

There's no question that DIY tube audio took off when the SET craze was brought to the US. The seminal article was Alan Douglas' "Tubes in Japan". Though Douglas correctly pointed out the deficiencies, the knowledge that thousands of people in supposedly sophisticated Japan were doing something was enough to light the fuse on this craze here.

Steve Sailer is one writer who has gone some way in exploring the reasons why Japan is the fad capital of the world, but that's another matter entirely.