This kind of component mounting was a fore-runner of larger scale integration.

Quite a bit of circuitry from those days was made like that.

https://en.wikipedia.org/wiki/Hybrid_integrated_circuit

Excellent mechanical properties (esp. with respect to vibration resistance) and more compact than the other mounting methods available at the time, it seems to me to have been the obvious choice for anything on spacecraft or aircraft.

I mean more specifically the way the components are flush-mounted, not in the standard DIP arrangement. They don't require holes drilled in the board, and more importantly, don't penetrate the board itself, so components can be mounted on both sides if necessary without risk of overlapping holes.

I can remember building computers in the early 1990s with logic boards that looked more primitive than what was in this module from the 1960s.

Apparently surface mounting was developed specifically for the Launch Vehicle Digital Computer: https://en.wikipedia.org/wiki/Surface-mount_technology

In Herman Lukoff's autobiography "From Dits to Bits", he describes building a radio where he surface mounted the components to the glass envelope of the vacuum tube. I believe that he constructed it before World War II. Traditional vacuum tube chassis were usually heavy metal assemblies so this was pretty radical.

Unfortunately, once the tube reached operating temperature, his painstakingly hand drawn traces and glued down components delaminated. However, it shows that people were thinking about that sort of thing.