Probably a little later than you were thinking, but for a period in the early nineties, between 1991 and 1994, Inverness had a dedicated sub-fleet of class 47s numbered 47671 - 677, which had a higher ETS rating than standard class 47s to cater primarily for the demands of the Inverness sleeper. They were often unreliable and were subsequently replaced, for a limited time, on the Inverness sleeper by pairs of no-heat 37s and generator vans. Four were absorbed into the Railnet programme (47671/672/673/675 becoming 47789/760/790/791 respectively) while a fifth (47674) was belatedly converted into the final "47/8" several years after the others, as 47854.
At the close of 1982, the Scottish region had the following train heat fitted class 47s on its' books:
47424 Eastfield
47427 Eastfield
47460 Eastfield
47461 Eastfield "Charles Rennie Mackintosh"
47464 Inverness
47467 Inverness
47469 Inverness
47470 Eastfield
47472 Inverness
47517 Eastfield
47541 Eastfield "The Queen Mother"
47546 Inverness
47550 Inverness "University of Dundee"
47562 Eastfield
47564 Eastfield
47570 Eastfield
47578 Eastfield
Plus 47701 - 712 converted in 1979 for use on the Edinburgh - Glasgow push-pull workings and allocated to Haymarket.
47424/427 transferred to Gateshead depot during 1983 and 47472 moved away at the end of the same year, while 47460/461 were reallocated to Inverness in 1983 and 1984 respectively, staying until 1990 when they were replaced by class 158s. 47464 was written off in a collision with 37416 on the Aberdeen - Inverness line in September 1986. 47492 arrived at Inverness in May of the same year.
As the eighties progressed and further locos were converted to electric train supply, additional class members were allocated to the Scottish region, including 47586/593/595/604/614/617/635 - 637/640 - 644. Most spent time allocated to Inverness at some point during the latter half of the eighties.