In this circuit, the integrated amplifier used is uncommon today. The circuit is from an American documentation from the 70's making use of a power transistor for output. A TIP32 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...