The tunnel mentioned at Manors station Newcastle would be to the Quayside branch I would think. This branch was origionally electrified in the days of the Tyneside suburban electrics and worked by two NER crocodile locos wirh dual overhead and third rail pickups. One is preserved by the NRM. In their final days, the early 1960's they were painted in NER light green by BR and they looked magnificent.
Goodness, and we are disappoined when a modern video isn't HD... Interesting few bygones and bygoings on the approach to Edinburgh. BTW I think the caption-writer meant Monktonhall, not Millerhill.
Nice to see the route pre-wires! I remember it well. Great video, though I found the constant questioning of the traincrew a bit distracting, if I'd been driving that I'd have put the person off at Darlington! Thanks for posting