This thing is said to emulate a 69 Marshall Plexi 50W on 10... Hmmm, OK - Here's the scheme :
It looks like this one was drawn by the great matsumin, one of the legendary Japanese DIY bloggers! Check it out, it's a fairly simple build!
Here is the original PDF Manual: Link!
Here's a decent demo of Hao Rust Driver in action:
Once again. A big Thanks to the Freestompboxes guys for getting this info together and to the people who created it in the first place!
Expect more schemes soon - or just join freestompboxes for a sneak peak!