I am not really disheartened, I have found, through Stephen (Cooper997) the correct racetrack and date where the surviving car (pictured) was originally seen and even found out there was an advert in that particular race meeting programme regards Jack demonstrating the car for the first time in Australia.
We have proved the one Jack was pictured in at Longford is a different car, but (so far) have not been able to get anything else on that one.
There is another in Queensland which I am waiting for pictures of, it was possibly always a Qld car and was raced up there in period??????
Michael (group7) sent a picture of one racing in period in Canada!
It seems incredible that out of a (rumored) total of 10 cars built at least 3 came to Australia and that two are known to still be in existence, and yet none appear to have survived in England. I am fully aware that in Australia at the time a Vauxhall Viva would have been of little interest, even though they did perform well in their class at Bathurst and elsewhere. I had sort of hoped the Jack Brabham connection might have raised a few more memories.
I have scoured Google for any references, contacted the various historic racing picture archives, etc. but I must admit I am running out of options. I am sure there is more out there, I will keep digging and see what we can uncover.