Ok I didn't know it was laminate, I missed that earlier, so the origonal core used some type of ferrite it looks like. If were using a max of 20kHz we need some pretty thin pieces here.
Your right about the microcontroller. It's mentioned in the WFC News Release issue no 10. There is a pic of it in that news release. It states that the chip is able to perform 1.6 million logic functions per second. I think I actutally have a picture of his final boards which shows the microcontroller on it.
If you don't have that news release it on tony's site, globalkast.org under documentation.