Well, the fault was two different ones,
The tuning meter problem was to do with the trimpots controlling the zero offset and gain. The one that controls the gain must have a bad area on the track, when adjusted outside this bad area, the meter works great, although probably a little inaccurate - I will aim to change this pot when I order some parts next week.
Next, the 'S' lamps - Transistor TR9 did test as good, but it had been installed wrongly. If you look at the circuit diagram, the configuration of the pads on the PCB is E B C, but the transistors legs are E C B!
It had been installed incorrectly, probably in a previous repair attempt. Upon swapping the legs of the base and collector, the lamps functioned perfectly.