We did actually go into small-scale production of consoles, amps, speakers, etc, and built some decent consoles for the lower$$ market. Did everything in-house except the anodizing of the aluminum. Spent many many hours hours drilling PCBs, loading PCBs, wiring the internal parts, building snakes with multi-pin connectors, punching aluminum plates, silk-screening, etc. As I said, a small family business, but with very few outside employees. I DO NOT miss those days, but I'm glad I did it.
There was one sound company locally that showed up for a gig ( I was playing at this one) with a console that was at least 6' long. Wouldn't let anyone near it at first, and they kept raising the back up and wiggling things in it. I finally got close enough to see the top, and saw that it was all plywood with one row of round knobs spaced 6" apart. Later that day they all went on break, but left the back open on it, so naturally I had to peek inside. They had a whole row of Shure mic mixers laying inside with "L" pads between the mic connections and the inputs on the mixers. I still don't know how it worked at all.