This circuit was found in documentation from the 90s. The transistors can be general-purpose equivalents. The circuit has two versions, one that drives LEDs and another that drives a relay as a load.
For those who like experimental circuits, here is a sequential flasher system with LEDs, which can be...
This circuit was found in an ancient American documentation. The integrated circuit is of the time...
This circuit was found in a 1977 Radio Shack documentation. The circuit is tuned to 1.4 kHz, but...