In late 70's I remember the BIA Heralds parked on the "North Park" opposite the South Terminal central pier occasionally sharing with Dan-Air 748's.
One of their Heralds had an "incident" at Gatwick in early 1975 when during the take-off the gear was retracted too early resulting in the aircraft settling back onto the runway which was then blocked for several hours until aircraft recovery was complete.
I think they also flew a Blackpool - Prestwick early morning mail/newspaper flight in the early 70's as I was fortunate to have flown on one.