Hi Randyman,
Yes, you named lots more. Another basic appeal of that era was that analog vinyl playback was relatively easy to understand. Digital technology is technically dense--incredibly so--which is why a lot of high-end vinyl aficionados hate it. They just don't understand it, whereas low-frequency tonearm resonances you could see--watch that woofer flap!--and warp-wow as the warped LP caused your custom tonearm to cycle up and down.
Do you remember the Disctracker, from Discwasher? I still have one. It was this tiny air-damped shock absorber you attached to the headshell beside the cartridge. It did the same thing as the flip-down brush on the V-15 series cartridges. I had one installed on a second turntable for my moving-coil and Grado MM cartridges.
And Chesseroo, the discrete 4-channel format really advanced cartridge design. It was technically premature, because the record cutter had to record a 40,000-Hz carrier frequency to carry the extra two channels. So the cartridge had to effectively track the 40-kHz carrier. It's amazing that it even worked!
Regards,
