In the 1930's the major British Banjo makers produced a lot of instruments for others, like small distributors, big shops and minor celebrities to re-brand and distribute. Some like Alvin Keech or JeTeL are fairly easy to find information on, but a lot of them I can find very little about beyond the fact that they branded Banjoleles, very often made by GH&S and including the Lion stamp, (it may be the case that some of them were House brands for GH&S?). There were also a number of small British Banjo makers/luthiers at the beginning of the 20th century for whom it is also difficult to find much information on but who did make Banjoleles, I am including here.
One final note and its a General one - If you see a small British made banjo instrument with 8 strings it is a Banjo Mandolin not a Banjolele ALWAYS
Columbian - Nothing to do with the Tonk Bros use of the brand name
Deker - made in the South of England and the one I've seen was a Tenor scale
Encore -
Eric Graham & Co - The button on the back of the headstock reads Eric Graham & Co. Makers London, may have been a maker or may just have been a shop?
Fitzroy -
Mamelok Bros. - A big music shop in Manchester founded in the early 20th c. and shut down in 1993. As well as being a local reseller they re-badged UK, and imported German Banjo Ukuleles with the brand Perfect Mamelok Tone
Maxitone - Says Equity 9 on the headstock of the one I have seen as well, and nothing to do with the Maxitone Banjolele sold by the US Distributor Bruno the Banjolele I've seen was made by GH&S so it may just be another of their House brands?
Merry Bright - Rose Morris made; not GH&S. I have also seen it suggested that this actually was a Rose Morris brand but have no definite proof?
Palitoy - A toy maker founded in 1909 and probably most famous for making plastic action figures. As with most of these sorts of business it went through a number of takeovers, finally by Hasbro who absorbed it in 1994. During the 1960's they had a go at making a plastic Ukulele
Roly - The name may not even be correct there was a hole drilled through the headstock logo of the one I have seen?
Swanee - Nothing to do with the US Banjo maker Swanee, (who didn't make Banjoleles), and probably Rose Morris made again?
Wallis (of London) - James Wallis of Euston Road, London was granted a patent for covering the banjo hoop with celluloid in 1889. I know no more about the buisness beyond this but I have seen a Banjolele baring this name from the 1920's (though it might be a low end Dallas rebrand?)