156s and 142s both work the same trains along the Tyne Valley and the coast line so a 156 vice 142 isn't rare at all. The Settle line 156 is 156484.
As Eezypeazy has said above, all trains that work Newcastle to Glasgow via Dumfries are ScotRail 156s, although there are a couple of morning services which use a Northern rail 156/142 from Dumfries to Newcastle.
As also said, 142s working Newcastle to Whitehaven and Carlisle to Middlesbrough trains are not rare at all.
RE: Northern Rail
![[Image: 0a85ed5b4e97324e338555472f222830.png]](https://public.railmiles.me/signatures/0a85ed5b4e97324e338555472f222830.png)