They were originally part of Claremont Garments which had a few local factories. Might have even been a joint venture with the club to get them up and running. Must have split off as a separate company further down the line.
With them being so local there was some sort of scam that went down where the lasses in the factories were hoying loads of new gear in the skips to get picked up later. There was a canny black market going on where you could get training tops and bench jackets for next to nowt!
From time to time clubs make their own kits as I presume they cover the lack of a kit sponsor by making more money per shirt sold. I can remember Southampton making their own kits under the brand 'saints' and leicester did the same with 'fox leisure'.