Well, yeah, I guess we have. In fact, not long ago I was cleaning up a
lab bench and found some of the old Telco style connectors, all gold
plated and pretty. I couldn't bear to toss them, even though the
chances of us ever using them again are somewhere between slim and
none, toward the none end of that scale. I suppose that any
special-impedance market that was large enough, we built for. Of
course the older audio generators (200CD et al) were 600 ohm.

Cheers,
Tom