Regal Zonophone 2
That was my thought as well. It made me wonder if they had any other material as yet unheard...
i think I've mentioned this before, but there are a lot of acetates to be heard at britishmusicarchives.com and Sir Henry @ Ed Debba.
That's true, you did point us to that interesting site, and I guess the comp Psychedelic Jumble a while ago was basically acetates as well.