Back in the day, this surely represented an achievement in high-density electronics packaging:
A view from the other corner suggests the layout wasn’t quite right:
It has no identification, the transistors have house numbers, and the PCB looks like a prototype. As nearly as I can tell from the capacitor date codes, it dates back to the mid-1960s.
Judging from the ugly solder and dislodged via rings, somebody had to apply extensive modifications after initial assembly; it trailed half a dozen red wires soldered to vias and components.
One hopes it eventually worked…