Thanks for the reply Dawn. I saw your bike on the LDMCC site recently - very nice. What silencers are fitted?
Today I visited the chap who's doing the restoration, to discuss the colours and layout. After reading all previous forum posts on the subject, and re-reading a pile of old New Conrod issues (1960's - 1990's) I can find nothing de facto (a term that looks progressively more misguided) and am beginning to come round the the idea that close is as good as I can expect - what with formulas changing, systems changing, time passing and nothing ever fully recorded.
However, the unrestored tank that I have has plenty of blue left on it (on the underside) and silver on top, which could be matched in a similar fashion to your machine. The blue on my tank which was painted in 1970 is slightly darker than the "Ford Fjord Blue" (ICI Autocolor: Q-XSC1431 8355 Fiord Blue 1977) mentioned by Frank Dolman.
My dilemma is whether to go with the 1970 colour already on my tank or Frank's "Fjord Blue".
The lighter Ford/ICI colour sounds a little like the lighter colour often referred to as applied to MK3s. But then if I am to believe my father originally had a good job done in 1970, club members of the time thought so, then maybe the slightly darker blue is what I should stick with... have I answered my own query?