I made some noise!!!
All three oscillators are using S9018 transistors on a 9v supply, with 5mm purple LEDs. It turns out I didn’t have any 10K resistors to put in parallel with the B100K POTs, so there’s two 4K7 resistors in series over each one instead. There’s no tone POT either, due to the lack of 47nF capacitors, which wont arrive until Monday, probably.
The oscillator in the left is using a 47µF electrolytic capacitor, the one in the middle a 22µF, and the one on the right a 2.2µF. I think I’m going to have to get a few more smaller ones to test with, along with some actual B10K POTs.
I built the first oscillator, and after watching the LED flash for a bit, plugged it into an amplifier. I was disappointed to not hear anything, other than an annoying buzz, like something wasn’t grounded properly. So I built the second oscillator, and again watched the LED flash, but with nothing being output. So I built the third oscillator, and it didn’t work at all. It was only at this point did I realise that the breadboard I’ve bought, don’t have the continuous red a blue lines on the power rails. A couple of jumpers and suddenly the thirst oscillator was working, and I had output. 
P.S. That bit of LEGO road, is a good thirty odd years old… 