I feel I'm going into unknown territories here, but it's a good way to learn stuff.
Layouts are usually drawn by people with knowledge far beyond mine, and mad vero-ing skills :)
Anyway, here is my take.
As usual, plenty of space left empty, I believe it will fit in a 1950B though. Couldn't find a better way to draw the vactrols, I hope they make sense. Anyone who wants to try this, read the manual first. It will help understand some stuff. Note that "Va" should be linked to the other "Va". D1&2 are necessary for the circuit to work right, but you can take one or both of them out as rate indicators.