In the 1984/1985 timetable the Aberdeens were still off Kings Cross, there were generally 2 per night with an additional one from KX to Edinburgh. The Aberdeens are shown as running via Inverkeithing, Kirkcaldy and Dundee.
To Inverness / Fort William, in the currency of the timetable there were 2 per night from Euston to Inverness with one carrying the portion for Fort William. I think it divided/joined in Mossend Yard or thereabouts. The Inverness portions are shown as taking about 45 minutes to get from Motherwell to Larbert so I suggest a direct-ish routeing via Cumbernauld.
The Fort William portion is shown as having a stop in Glasgow QS.
There was also a Euston to Perth service shown stopping at Coatbridge and Cumbernauld (amongst others) on the way. This also carried a portion for Glasgow dividing/joining at Carlisle and running via the G&SW.
There was also the internal Inverness sleepers from Edinburgh/Glasgow QS splitting/joining at Perth.
Glasgow/Edinburgh also had the sleeper from the south west which split/joined at Carstairs.
I did a few of those in my younger days