This circuit has the intensity of the signals controlled by the light that falls on the sensor. Note that it is not a frequency-controlled oscillator. Equivalent transistors can be used.
This is an old test circuit for integrated TTL counters, feeding a Nixie tube, common at the time....
This old oscillator using germanium transistors has a high impedance headphone as inductor to...
This preamp with several inputs using germanium transistors from the time was found in Japanese...