I recall being class 47 hauled in about 1982. The seated coach was a mark 2a/b/c (the type with no air con)
2Z, the Mk1 sleepers allocated to the Scottish Region having vacuum brakes.
You must have been unlucky. 37s weren’t allocated to Inverness until the spring of 1982. (Source: Shed by Shed, Part Eight by Tony Walmsley.) Perhaps they were doing a test-run to see how the class performed.
Indeed, and a significant acceleration was made in 1983 and 1984 to Far North services as a result of the improved performance. The Kyle Line seemed to hold out on 26s for a little longer.
Having had a look at my May 81 - June 82 GBTT it would seem the Edinburgh - Inverness sleeper service also had a call at Stirling as it did in the late 80s so would not have gone via Fife (engineering or other disruption excepted of course!).
The routing via Stirling began with the 1982 "Tartan Taktfahrplan", with one Edinburgh/Inverness service each way being routed via Stirling instead of Fife to offer improved local connections (in fairness via Stirling was the normal routing after the Glenfarg route closed but the Ladybank line was used after 1975 with Edinburgh-Perth/Inverness trains then going via Fife again) This lasted until 1985 when all Edinburgh-Inverness trains were routed via Stirling. This changed again when the augmented Sprinter Timetable with 158s was launched giving a near two-hourly pattern Edinburgh-Inverness service.
1) what was the usual haulage? I remember it often being class 26/27. Was that typical?
In earlier years, 24/26s sometimes two or three depending on loads/requirements. 47s were more common by the early 1980s. 40s also appeared in the mid/late 1970s, operating the daytime Inverness trains sometimes, but they were preferred foe Aberdeen jobs.
Did the Edinburgh leg run through fife or did it come through Stirling as well?
Via Stirling, but the daytime services had both routings through the years.
I have read that there was one mk1 1st/2nd class sleeper on each leg but what was the formation? I assume a BG or was there regular seating as well? Was this the same for both legs?
In Mk1 days, yes. Both Glasgow and Edinburgh portions had one SLC each as the sleeping accommodation. Each then also usually had 1 or 2 TSO and a BSO for seats, plus several NDV. You had NDV to Aberdeen, to Perth, to Inverness. At one point motorail vans to Inverness were also conveyed.
Things changed when the Mk3 sleepers were introduced, formations being greatly simplified.
There were 5 circuits from 1985 -
Glasgow-Inverness
Glasgow-Aberdeen
Edinburgh-Inverness
Inverness-Glasgow
Inverness-Edinburgh
Each circuit comprised a single SLEP.
Going north the train from Glasgow-Inverness was:
BSO-TSO-TSO-SLEP-SLEP*
(* for Aberdeen)
The Edinburgh portion was identical, save having only one SLEP.
The Glasgow-Aberdeen sleeper was detached at Perth when the portions from Edinburgh and Glasgow were being combined. It was shunted into a bay platform and then left, after a reversal attached to the 0105 Perth-Dyce.
Being a unidirectional working, it returned empty in the 1105 Aberdeen-Glasgow push-pull.
The seating coaches came from Inverness' allocation for the day trains to Edinburgh and Glasgow, the BSO-TSO-TSO sets forming their own circuits separate to the remaining two vehicles these sets conveyed - TSOT, CK. The midday service from Glasgow to Inverness had its BSO-TSO-TSO set swapped with another identical set off maintenance during its layover before it returned to Glasgow.