I can't find any photos of the Dartmouth aircraft (at least, in colour) but this was one of the Chippies that we used at Linton on Ouse for the BFT. IIRC, the colours were identical for the RN BRNC Flight, so I'd be a bit sus of those shown in the photo of 511.
BEX, thanks for the list of numbers, are/were you organised enough to keep them for 705 as well? I've got some halfway decent pics of 12E's and a Whirlwind........
I'd forgotten the joys of flying in Yorkshire in midwinter