I've discovered http://runoffgrove.com - it has heaps of schematics, layouts and audio recordings of how the pedals sound. I've decided to try a distortion pedal called the May Queen - meant to sound like the lead guitar from Queen.
This pedal needs a J201 JFET transistor, and these older transistors can be hard to find. It's not available at any of the usual electronics retailers in Australia, unless I want to buy SMD devices. I did some reading online to find alternatives, but everything I see being suggested as an alternative is also not available. Some of the USA based electronics sites have them, but they are $5 each, with a minimum $50 order to avoid horrific shipping costs.
Searching on eBay shows I can get them from China for about 10c each... which almost certainly means they are fakes. I've bought some to try out anyway.
The build was pretty simple, but the pedal basically did nothing when I got it all finished. I blamed the eBay J201, assumed it was a fake that didn't work, and threw the circuit in a drawer for a few weeks.
Later on I went back to it again, and realised that I read the J201 datasheet completely wrong - I had substituted the 2nd and 3rd pins. Boy did I feel like an idiot, blaming the cheap Chinese transistors, when I'd actually just wired the board wrong. It wasn't easy to rewire on the tiny little board, especially after I'd jammed it in to a tiny enclosure, but eventually got it working.
The sound is harsh - definitely works as a lead guitar distortion. Not sure if it sounds anything like Queen...
I've also just found Small Bear Electronics, who specialise in guitar pedal stuff. They have verified genuine parts, so I'll see if one of their J201s make a difference to the sound. Again, the downside is the shipping costs from the USA.
[video width="640" height="360" m4v="http://graybloomfield.com/guitar/wp-content/uploads/2016/10/mayqueen.m4v"][/video]