OK, second attempt ...
Red G Tourer in centre of line-up is nowadays mine, as taken in 1966 - with a green tint-strip. The lettering (I have another pic from a different angle) is the timeless slogan "You Can't Beat a
BOND".
I confirmed the date by examining the long "Illuminations" poster at top left: it says the switch on, on Friday 13 August, would be by Roger Moore. Morecambe's publicity office (by almost
instant email reply to me!) confirmed that he did the switch-on in 1965 (and I checked: 13 August was indeed a Friday in 1965). As the poster is faded and torn, it would be for the
previous illuminations, so this event was the 1966 one
The photo also shows the existence in 1966 of screen-top lettering, on the red-hooded Mark D, in second position. The first bit says "Slough", so I'm guessing the second bit said something like "BOC".
It's good to see that, at this rally, people not properly dressed in suit and tie were kept in the area
behind the cars!