D-shell connector age?

Anyone know where D-shell connectors first appeared on equipment? Interesting thread going on in a local group at the moment about why SCART [1] sockets are so horrible and nasty (prone to breaking pins, difficult to line up, prone to falling out etc.) and why something better, like a D-shell connector, wasn't chosen instead. Thing is, SCART was apparently first used in consumer A/V equipment in 1977, which probably means it was thought up in the mid-70's. Edge connectors and/or circular DIN connectors were probably more common on computer equipment of that time, but were D-shell types around by then too? [1] For the non-Europeans, SCART is common on all A/V equipment in Europe and provides component RGB (as well as composite) interconnect between devices, along with stereo audio channels, sync lines, remote device standby control etc. cheers Jules