Spent this afternoon building a compact modular base for the UX-4 sockets, a custom tag strip and the filament bias resistor array. Given the very low power dissipation on the filament resistors they can be placed below the valve socket board to minimise space. The actual size of resistors is a killer, but I have a stock of these lovely wire-wound ones:
Also the gyrator boards were mounted on top of the output teflon capacitors, again to minimise space. The trimpots to set the anode voltage are located at the top for handy adjustment if necessary:
