Chris55000 - on the EPE online shop all the PCBs appear to be available:
https://www.electronpublishing.com/p...former-tester/
I was toying with just making it on perfboard, or perhaps some good old tagstrip, but it would certainly be easier to use their PCB!
I thought a nice wooden box with a hinged transparent lid for the capacitor in question (some brass plates, too?) would be more appealing than the plastic box they built it in, so I'd be investigating that once I've sharpened my dovetail saw...
MrBungle - I don't know enough about the subject to see if those parts are suitable, but many thanks for looking through your box. Or perhaps Mrs Bungle should be thanking me for providing the cupboard-sorting impetus!
I've attached the diagram so you can see how the circuit functions. The transformer is part of the step-up from the DC supply, and the winding instructions are included.