Claud Butler made by Holdsworthy Co. Plenty of details out there, Holdsworthy bought the name when Claud went bust. Most surviving Claud Butlers are after July 1958, not Holdsworth but The Holdworthy Company, who were major importers and wholesalers to the cycle trade.
Holdsworthy produced frames, generally to standard designs, at a competitive price. I was retailing them at the time.
Up till closure Claud Butler made some modern classic quality bikes.
Keith