Not just a "belief"; it's fact! The CDR never painted domes black on red locomotives. Like many another livery faux-pas, this is a product of a lack of accurate research at Whitehead; we've TWO of these things with black domes now.....! Mind you, not just the domes, but often the tops of the water tanks, the cab front and rear, and most of the boiler ended up caked with so much soot and general gunk that it might as well have been painted black - same with bright blue GNR locos. I'd say if someone painted 171's or 85's dome black, there would be war...... Many CIE green or grey engines, similarly, ended their days so filthy that they could have been painted lime green, tartan and flourescent pink for all anyone could see.....
Rant over; to Ernie's latest pictures - absolutely SUPERB stuff.
That's standard GNR 3rd class material of the day. The C&L coach 1L has what was then standard CIE 3rd / 2nd class.