There are several "inaccuracies" in Bacon's book. I purchased my '73 Mk V Roadster new in May of '73 and it has a build date of November '72. Therefore Bacon's statement that the first MkV roadster was built in March of '73 is one of these.
I am sure there was a period of time when the factory was building bikes on the "new" MkV specs while cleaning out the bins and building the "old" Mk IV bikes at the same time. I find Bacon's book and others valuable reference, but definitely not the last word on authenticity.
By the way, Chuck. A friend has my side covers with original "fireflake blue" paint and his painter is trying to match it. He has spoken with Les Emery (Norvil) who says he once did the paint at the Norton factory. The original Fireflake blue on the '73 models is a fine flake and appears to be a translucent (sort of candy) blue over a silver base. When they are finished I can get you the details and paint codes they use. I'm thinking of having an extra set sprayed up myself, as my originals are beginning to look like they are 32 years old!