It was about seven years ago so my recollection is a bit vague, but as far as I remember it was an unrestored Commando 20M3 with the Dominator silencers and I *think* it was a round badge tank (and I think the badges were missing?) with a very low production number, that is why the dealer wanted a fairly high price for it (£3600GBP -I remember that, which was a bit high for that time!) but there is no way I could say that it left the factory as a green model.
There's a green round badge (20M3) model shown in Don Morley's Norton book but it is probably a restored bike, I would expect a restored bike to have the correct colour scheme but-who knows!
'69 Fastbacks in *BRG were certainly fairly common in the UK (I seem to remember as most early UK Commandos were Fastbacks until the Interstate model came along).
*This particular colour green may not have actually been known as British Racing Green?
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Update
Actually it was over nine years ago! Bl**dy He*l doesn't time fly when you're enjoying yourself!
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Futher update
As well as Roy Bacon, authors Jeff Clew, Steve Wilson and Mick Duckworth all mention either 'Green' 'Dark Green' or 'Forest Green' as being a '68 model colour in their books.