This is one of the antenna tuners that RACAL designed.
It uses a Comet 650pF 5 kV ceramic vacuum capacitor and a 500pf variable capacitor.

The unit also has 2 vacuum RF relays.
The coils have an internal switch that is built into the core.
Further, this tuner contains an inductor with several taps, two 11-position switches for the coil taps, power sensors and a power meter.

The unit weighs 11 kilos.
This is all the information I have on this unit.
Here is a view of the inside, where the unit stands on its rear side.