So what the heck did I just pick up?

[Gregory Beat]

Beautiful front panel (1970s design).  
It would make a nice front panel for a DIY Computer.
—
It is an RS-423 control/switch panel.  
RS-423 is an EIA/TIA serial communications standard, BUT there is no common pinout (standard) for RS-423. 
==
RS-232 was defined in 1962 by the Electronics Industry Association (now the Electronics Industry Alliance). Control of the standards definition was passed over to the Telecommunications Industry Association in 1988. Since then, standards documents relating to RS-232 are referenced by the code “TIA.” The standard is currently known as TIA-232-F. 
RS-432 was a faster version of RS-232 — BUT it was not widely adopted.
https://en.m.wikipedia.org/wiki/RS-423

The BBC Micro computer used a 5-pin DIN connector.  DEC used it with their Modified Modular Jack (MMJ) connector. This was sometimes called "DEC-423".
RS-432 was implemented in Apple Mac computers and the Enterprise 64 and 128 models. All other hardware manufacturers stuck with RS-232. 

g. beat
elmhurst, is

Midwest VCF : September 14-15, 2019
http://vcfmw.org/

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