These are the circuit diagrams:

This is the system diagram

System diagram

This is the Micro-Controller:

Interior Layout

This is the new hours counter:

Power

This is the new tens of hours counter:

Processor

This is the knob board diagram:

I/O

This is the control switch noard diagram:

Controls

This is the Transmitter assembly diagram:

Counter Cable

This is the original 1965 Nixie counter blueprint:

Counter