Cgs synth

Hi anyone
Recently I found Ken's page about his Modular synth. It's a great page!
So now I've a question about the real Ringmodulator:

Somehow I couldn't find some rigt transformers.
What type of transformers are used in the Ringmodulator? It would be
nice if you could tell me the ... as well.
Could you give me a suggestion about the Ge-Diodes? I read somwhere,
that usually Shottky-Diodes (I don't know if they are caled so in
English) were used for ringmods.

I hope you understand what I'm writing... English isn't my mother-
tongue...

Thanks for your help!

Cheers Luke