About the manuals - it's highly unusual to say where the voltages are referenced to - it's a note that most people won't read, and the ones that do will not understand. It's like asking the question "how tall is that tree?" and getting the answer "well, with reference to the surface of the earth, it is x feet tall". You don't need to know that the ground is x feet above sea level, or that there are roots extending down. The measurement is with reference to the ground. As you do more with electronics, this will be second nature as well.
I'd stick with just the single neon for the moment. If you need them. let me know and I can send you some matching ones, otherwise it will look weird. There are also a few things t know when doing that - you need a resistor per neon, otherwise one will always steal all the current from the other and only one will light up.
All finished (just the case left) and all working with one exception:
One of the tubes are flickering alot when cold, but seems to stop when it gets hotter, and is almost stable after the one minute test cycle finished.
It is the same tube no matter where it is placed, and all solderings looks fine on that board, so i suspect it is the tube it self being the culprit.
Yeah, that was my thread. I was wondering about it too. I had been reading this thread when it's title changed with no explanation. If Ty or Ian could fix it, that would be nice.
@roadrune - I agree. It sounds like you got a marginal / bad tube. Seeing that the tube is probably over 35 years old, it's not uncommon for some tubes to out-gas and cause flickering. Buy yourself a couple spares on eBay, replace it and keep an extra because they won't decrease in price.