A brilliant picture Brian !!
I'm rather fond of and know Halls quite well as I leaned to fire, and was passed out as a fireman on one, albeit an un-modified hall.
JB.
One of my ambitions is a cab ride. There's nothing to stop me doing one on one of the preserved lines I guess. Just a question of getting round to it. It's all a bit clinical when compared with the BR days, though.
Actually, on reconsideration I think this is an unmodified Hall. Didn't the Modified Halls start at 6959?
As a side comment, when on the West Highland in 2012 I specifically looked in the cab of the Black 5 to see what colours it was painted. (In fact I was kindly invited on board by the crew). At first sight, despite the sparkling external appearance it appeared to be a uniform grey/black but on inspection the area above the waist was definitely lighter and when the grime was removed it was definitely cream above the waist line. I'm not suggesting that this is useful prototype information as the loco is preserved, but it rather demonstrates the need to look at loco cab photos ex works. Actually, I also believe that ex LMS locos were cream above the waist line in BR days, but I can't remember the reference for that!
While I'm at it here are some other cab photos of ex GWR locos (some are on my prototype photo thread already). You'll have to ignore the objective of these photos which was to record the backhead and controls within the limits of the camera I had at the time and concentrate on the cab sheeting which appears in the background of the shots.
Firstly an unsatisfactory and out of focus shot of 4079 at Swindon on 23rd May 1965. It was immediately ex works and there's no evidence of a light coloured top bit of the cab.
6111. Southall. 5th December 1965. This was at or just before witdrawal and there's no evidence of a light coloured cab - but in this case I'd guess there wouldn't be anything to indicate that, even if it actually was cream.
6143. Southall. 5th December 1965. Same situation as 6111 above, but the lighting is a bit better.
Same date, different loco and class. This is 6859, also at Southall.
Finally the cab of a working 9740 at Swindon Station in May 1959.
I have some from other regions too, notably the Southern. A West Country most definitely has a green cab interior, and that was a working loco at the time. It suffers the same problem, though, of seeing in detail what's above the waist line. However, there is some evidence that BR (SR) locos were painted a sort of bauxite above the waist. A colour photo I have of a BR (LMR) Jinty cab certainly suggests that this was cream above the waist line.
All in all it's a bit of a minefield. I suspect that, at least in part, the colour of the inside of the cab was decided to some extent at least by the local works despite what may have been written in any livery instruction manual. We know that, from time to time there were subtleties in different lining patterns, numberplate colours etc, so I don't see why that should not extend to the interiors of cabs!
I reckon Rule 1 applies. If anyone tells you that you have it wrong be very grateful as they obviously have the ex-works colour photo pre-1968! I'd love a copy for my collection.
Best regards.
Brian