This circuit has `suffered` a lot of modifications over its long life... Even the lettering on the integrated circuit was partially erased of the years.
The main motive of the mods was not that the circuit didn`t work right, but were several tries to add some kind of frequency indicator to the receiver. The left RCA plug and associated components are witnesses to the last version, adding a FET buffer amplifiera and taking signal from the oscillator coil.
None of the indicator systems was satisfactory, and the actual stability of the receiver oscillator was so good that it wasn`t really necessary either. A simple system with a preset resistor for each of the the desired satellites was more than enough