Okay this it.
The heater are green and black twisted together.
The cathode wires are yellow.
The plate wires are blue.
The control grids are light green.
Earth wires going to the earth bus across the pots are black.
The screen grids of the output stage have a bus wire going across with yellow insulation.
There is white or grey wire going from the output stage control grids to the last two decoupling caps.
The power supply wire colours are White, red, blue and the earth is black.
I did talk to Matt Taylor who was as always able to shed light on all of this.
Matt tells me this is the accepted convention.
Black: Grounds, grounded elements, and returns.
Brown: Heaters, filaments, off ground.
Red: Power supply, B+.
Orange: Screen grids.
Yellow: Cathodes.
Green: Control grids.
Blue: plates.
Grey: AC power lines.
White: Above or below ground returns, AVC etc.
Sorry about this omission. I think it didn't even occur to me at the time that this sort of thing was important.
