[Arran]

Fred;
  I'm not sure how the tuning light or lights are supposed to behave in this D-F Lyra model, on my Rogers 10-60 the tubing light stays bright when it's off a station, but dims when it's on a station. Some of these Rogers built sets had a tube dedicated to the operation of the tuning light or lights, I can't tell whether this set has one or not, but the light is connected in parallel with a 8600 Ohm resistor, and in series with two 10K ohm resistors, and then those are paralled with a 20K Om resistor, in the B+ circuitry. If the diagram on Nostalgia Air is correct then this set should also have variable IF bandwidth, which is what the arrows through the IF transformers are supposed to represent, it's a form of fidelity control, try playing with the tone control and see if the tuning light changes it's behavior. 
Regards
Arran