Can someone educate me on the approximate periods of the different case makers used by UG? Or point me in a helpful direction?

I've seen passing references scattered throughout old threads like this one. And I've seen the hallmarks section of Sala's book. But I'd like to learn more about any others that were used.

Spillman, Dennison, Henri Jeanneret? I presume these are 1930s-1950s? I've seen what appear to be references to Zenith cases - were these 1960s-1980s Space Compax, Polerouter Subs and the like?

Are there any rules of thumb, or approximate periods these were used?

Thanks