Yes, Holsters Unlimited where based in the Liverpool area of the UK but sadly folded quite sometime ago. They mainly manufactured holsters for the police and professionals. When I was a member of the Cheshire Police they where out initial providers of leatherwork in about 1975 'ish, prior to that officers going on an armed operation used their sky rocket!
It coinsided with the issue of our first modern revolvers, S&W M10 and M36 (CID Officers)..... Likely if it's an 'Upside Down' holster it was for police use................ Cheshire is about 12 miles south of Liverpool....