I'm aware there have been 2 versions of the choc/cream BB made 1934/1960 & also the 1969 blue/grey version.
Was there another version produced in blue/grey at the same time the 1934 choc/cream version was released ?

Await the more knowledgeable and the always right brigade  but as far as I know there was only 3 all of which you have listed

Only three types made.

1934 Pullman livery and 1967 blue grey were made first.
Then there was a re-run of the 1934 Pullman version the following year. There may have been a re-run of the blue grey at the same time, but there has always seemed to be a surfeit of blue grey and a  shortage of 1934 ones. When they did the re-runs they did not change the running numbers/coach names.
Last year there was a 1966 version (labelled 1960 but Small Yellow Panels were only added quite late in the day).
That's all.
IIRC Hornby have done other intermediate versions between 1934 and 1960 in OO (namely post war and pre SYP)

HTH
Bob