Hey-Hey!!!,
The Gunievere is a good starting point for the project. I know I don't need a whole lot of power. More power is more of an exercise, than a project goal. In the winter, it is a neat basement heater that's sure...:-).A while ago I was contemplating a special run of Nickel laminations. Looke like a cut C-core will be even more useful. The short run of micro-crystaline or amorphorous alloys will be coming close to parity with it and each has its own set of core qualities to play with. Read-read-read, and read some more. There is nothing magical or mythical about TX design. Dave Slagle and his group at Intact Audio are qute open to experimenting with all sorts of inovative magnetic designs.
cheers,
Douglas