Arthur,
I'm not sure what system this console was hooked up to at the dealership, late 60's or 1970, do to rapid growth, the system was changed about 4 times in the span of 10 years.
I know this console came to us when the old key system left, about 30 6 button phones, and were replaced with about 45 2500 sets.
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Ok did some digging, Arthur, sorry, I see now that we must of had a Leich PABX and this console was wired directly to it.
I found an interesting thread
Leich 40 / 80 PABX Turret The Mitel must have come after the Leich PBX which would have been in the early 70's
