I've seen this question raised on a couple of other sites, but not an answer. I've had a quick check of the books to hand and all I can offer is:
According to Peter Tatlow "LNER Wagons" the LNER used ".........Brown red oxide for all vehicles fitted with automatic brake............although the specification for this colour was changed to bauxite around 1940, the appearance seems to have remained much the same...................."
In David Larkin "Pre Nationalisation freight wagons on British Railways" he says...........vacuum-fitted stock.........bauxite (red-brown).................
Sorry, that is all I can find.
Regards
Paul
According to Peter Tatlow "LNER Wagons" the LNER used ".........Brown red oxide for all vehicles fitted with automatic brake............although the specification for this colour was changed to bauxite around 1940, the appearance seems to have remained much the same...................."
In David Larkin "Pre Nationalisation freight wagons on British Railways" he says...........vacuum-fitted stock.........bauxite (red-brown).................
Sorry, that is all I can find.
Regards
Paul