This has now been traced by Aion FX – it turns out the NG-3 is very different to the NG-2. Miles apart…
While this still makes for a decent fuzz, it’s NOT a NG-3. Layouts have been removed for this reason.
The Pete Cornish NG-3 is pretty much the NG-2 with the trimmer to bias the last stage placed externally – which is a great addition, even if the knob count starts to get a little high.
The front end is the first section of the Cornish G-2 (a low-gain Big Muff with germanium diodes), and the last stage is a Fuzz Face variant.
This should be built with the usual Cornish buffer, running buffered bypass. Hardly the end of the world if you opt to use a standard unbuffered true bypass.
As I’ve never seen a schematic for the NG-3, this is my work-a-like. I’ve used a 25k pot as the bias pot in my builds, as I preferred the range. I have had someone else say that they preferred the 50k, and another used a 20k pot without issues. Either way, it’s best to have a low-value resistor at the end of the range to stop the circuit from completely turning off – I use 4k7 for this, 8.5k has also been reported as a good value.