25kV

Looks like it carried the slightly larger-than-standard "Scottish" size Rail Alphabet numbers, which are available in a pack from Fox Transfers: https://www.fox-transfers.co.uk/transfers/standard-blue-scottish-loco-livery-elements

Perfect start for your model of Vic Berry's, circa 1987. ;)

Yep - I only realised after leaving the site that the standard base was the next bar up! The illustration where I've marked rough heights (based on eyeballing in the "base" I measured and scaling from that) was the closest to straight-on that I could get to today, without a huge amount of perspective. :)

My long-dormant casual interest in pylons (sorry, Transmission Towers - my late brother-in-law is turning in his grave), which entirely originated from driving repeatedly past the Ribble Crossing age 4 with my grandparents, has apparently been reawakened by this thread. :) I noticed that the apparently unusual Kintore-Beauly line is mentioned a few times (and that tower dimensions were unknown, according to the fascinating pages linked above); since I can almost see said line from my front window, and cycle under it almost daily, figured I might be helpful and go out with a tape measure. Some photos and rough dimensions from today's bicycle adventure here: http://25kv.uk/B2K.html

I think that's just the transformer header tank on the roof of the 86 - pantograph observation ports were usually inserted in the space where the second pantograph would theoretically go. Also it appears to be missing some roof equipment and buss-bars - the pantograph looks like it's incomplete too. The 83 has had its middle window replaced with a grille on the corridor side, but it doesn't look like the air tanks are in place yet (they would be at the nearest end where that shelf-like structure is visible. One thing that's very clear is the difference in shade between electric blue on the 83 and the darker blue on the 86!

You could always send the Aberdeen branch along the flatter side of the hills ... maybe down to Coupar Angus, across to Forfar and then up via Kinnaber Junc... wait. That sounds familiar! ;) Sorry - unhelpful reply, I know, but I drove through Blairgowrie yesterday and got all excited.

The alternative "what if" for the GC would have seen the 1500V DC wires extended south from Sheffield - as I understand it the original plan was to build a total of 27 class 77s (EM2) to cover the whole London-Manchester service. Alas...

It would largely depend on how close to the terminus the two lines converged and, as others have said, what the operating requirements would be. While Leeds (City) is not a terminus, when it was first electrified in 1988 or so, only the 'undercover' through platforms (and associated bays) were wired. The terminating Aire Valley platforms remained unelectrified, as did the Trans-Pennine through platform and goods loops on the south side of the station as well as the parcels bays. Later the whole station was wired with extensions to electrification in the area. Interestingly a spur leading onto the old Holbeck viaduct was electrified in the initial wiring program, though later removed - and probably never used by an electric train in the meantime!

I've lived ^here^ since 1994, and instantly recognised the works from your close-up shot of the door. Amazing model! Sadly the real building is no more, but I did grab a few photos as it was being demolished. Perfect use of the haar.

For anyone interested, I've added a new page to the APT Formations site which compares the various Hornby models available/proposed with reality (as it is currently understood!). It's intended as a bit of fun, but may be helpful to those who want to make their model as authentic as possible. The page is accessible from the main site menu, but here's a direct link: http://www.25kv.uk/APT-models.php

There is a tiny bit of evidence that 370004 received a black front - but none that it ever ran in traffic with it before being stripped for parts at Derby, so Hornby may be barking up the wrong tree there (there are some mis-captioned photos out and about which purport to be 370004 with a black mask, but it's possible to identify the actual unit through other means). I've only so far seen one instance of a yellow-fronted half-set running in service with all its trailer cars, and that was 370005 paired with 370001 on the ill-fated special that derailed near Carnforth. The most logical choice for another black-fronted set would be 370005/370006 which were the first to run with the masks, and in a full 12+2 formation. 370006 was also the unit used to launch the public service in December 1981 (paired with 2-car 370002). Another option would be 370007 which was ironically always a full length unit, and handled all the later public public services in 1984/1985. (Of course, none of these sets had correctly-numbered trailer cars!) Link in signature for details of known formations and livery variations.

Another late reply... The ECML coasting tests used three trailer sets - 003, 006 and 007, with power cars 49001 and 49003. In the Heaton photo what you're seeing is 49003, Test Service Car 9 (ADB975631), then the three cars of 370003 (behind the HST TGS); on an adjacent siding, partially hidden by the Mk2 First, is 49001 and the six cars of 370007. 370006 (not in the photo) was a two car formation with its nose cone removed, and was always the end coupled to the propelling Class 37s. One or two power cars and either 003 or 007 would form the rest of the test rakes - I've seen most combinations in photos of the runs! :)

A very late reply, but I've only just joined! The 1979 record breaking set would have been 370001+370002, formed 48101, 48206, 48601, 2 power cars (numbers unknown at this time), 48602, 48202 and 48102. 370001 was kitted out with test equipment at this time, with TS 48206 being essentially a lab coach. The Euston-Glasgow record was set on 12th December 1984, and the train would have been 370007+370006, formed 48107, 48201, 48406, 48303, 48503, 48607, 49003 (probably), 49006 (probably), 48602 and 48106. Of passing interest, TBF 48602 was part of both record-breaking trains, and is now preserved at Crewe.