I found this and this

During the early days of 1940 a popular dance caught on called The Black-Out Stroll and it was recorded quite widely by many of the Dance Bands of the era...A colleague of mine told me that it was also recorded by Oscar Rabin and His orchestra on Rex R 9710 but apart from a questionable reference in one book that I do not have a lot of trust in I have drawn a blank....Can anyone confirm this at all.....Do you have the record or a photo of it even......Never on any Oscar Rabin compilations so I am beginning to have my doubts

There was a Rex discography published in the 1970s. I can email it to you if you want, as the 78rpm Community website seems to have gone now. There is also the book British Dance Bands on Record which can be downloaded free (click the link). It would mention this recording.

Thanks for finding that. I have a bit of a soft spot for Oscar Rabin ( wasnt he associated with Wimbledon Palais ?)