This power step for relay activation was found in the 1964 RCA transistors manual. The circuit is of the NF type and the transistors admit equivalents. R4 depends on the drive voltage.
This shield, found in old English documentation, appears with variations elsewhere in this section...
This complementary or bilateral emitter follower was found in American documentation from the 90s....
This configuration that functions as a zener diode was found in an English publication from 1976....