They're bypass-capacitors for the cathode-resistors on the UAF42 1st-audio and the UL41 audio power-output stage.
Thanks for the vital tip I won't put power to it till the Plessseys and "that capacitor" have been changed.
I'm a valve dummy I want to see it work if I'm lucky.
I normally fix cars
But I have done the RAE and had a licence for 20 years.