Stupid old lens question

The next old lens I'll be listing is a "Greens Federal 135mm f2.8" - but my memory is letting me down completely about Greens. I think I remember a 1970s UK photographic chain with shops that did their own brand stuff (actually Unitor etc. with their name on the lens) but I'm really not sure this is right. Was it part of another company? Or a manufacturer in their own right? Anyone remember? Or got old copies of Amateur Photographer to check?

Later - found this, which seems to confirm it was shops:

http://www.bob-farley.co.uk/catalogue/index.php?/tags/106-greens_cameras

Think they also did mail order.