I haven't listened to the video because the sound on my computer doesn't work..
But according to a feature in the current issue of Octane magazine this car was actually meant as a successor to the AC Ace, which AC had decided by the early 1960's had had its day.
However, events overtook it when the Cobra became such a hit, and as it was a similar sort of concept albeit it with smoother body but the same engine, AC decided not to proceed with it.