KotangaGirl, JackDownUnder & Robd, thanks for the kind words.
Jack re post#361, the 11:20 a.m. out of Kings Cross during 1914 was a summer working with ECJS coaches for Edinburgh, Perth, Montrose and North Berwick. The North Berwick through coach was a 65ft6in 12 wheel matchboard Diagram 45 BCK (2-3) built at York in 1905. It was selected for its luggage capacity in the guard's space.
Matchboard coaches were prominent in the GN&NEJS, with 10 of the 36 coaches being of the slab-sided matchboard type.
At Darlington a N.E.R. through coach from Keswick was attached, bound for Newcastle. Most likely it was a non-corridor type and I will be using an N.E.R. 52ft Clerestory roof BCL (2-3). I think that the duration of the journey justified a Brake Composite lavatory!
By 1922 the 11:20 a.m. was a completely different train. Bradshaw's GNR Table for the north describes it as a "London, Harrogate, Scarborough and Glasgow Express" and "Luncheon Car London to Scarboro". The GNR main core of the dining set did go to Scarborough, but a GNR portion was removed at 2:32 p.m. at Doncaster for Harrogate going forward at 2:44 p.m via Church Fenton (arr Harrogate 3:45 p.m.). At York ( arr 3:21 p.m.) the main GNR core for Scarborough was moved to the Scarborough platforms but an ECJS 3-coach portion for Glasgow Queen Street was removed and joined to an NER Leeds to Glasgow portion made up mostly of a dining set. The NER table for the north describes it as "Restaurant Car Express York to Glasgow".
An NBR through coach from Scarborough for Glasgow was added to the ECJS-NER portions for Glasgow. Finally, a 4/5 coach portion from Southampton Town (dep 7:36 a.m.) bound for Glasgow was added. This stock was NBR or LSWR on alternate days and routed via Didcot, Oxford, Banbury, Nottingham Victoria and Sheffield Victoria. Bradshaw's notes a Restaurant Car was added at Oxford, but whether it was GWR or GCR is unknown. It went all the way to York. From the description in Bradshaws in the LSWR section it seems that there was at least one through coach, possibly always an LSWR one, from Southampton Town bound for Scarborough. So, the train left York for Glasgow with around 12 coaches while the 3 GNR coaches and 1 or 2 LSWR coaches headed for Scarborough and the GWR/GCR Oxford dining car waited for its return working (the next day). A lot of shunting at York!
Update: The restaurant car added at Oxford at 10 a.m. was, in my opinion, a composite coach and going all the way to York would not have made a return trip south that day. I had thought about it coming off the train at Sheffield Victoria (1:51 - 2:00 p.m.) but the table for Sheffield to York describes it as having a "Restaurant Car" and stopping at Rotherham & Masboro, Pontefract (sets down by request) and Burton Salmon (change for Selby and Hull). I would choose a GCR coach but there is wiggle room to make it a GWR one (though probably the oldest one they could spare).