it was made by......
Dudley appliances which was a manufacturing division of CWS (co-operative wholesale society) in Dudley, West Midlands for bustler towards the end of the bustler vac companies days circa 1955. Dudley appliances made all sorts of domestic electrical appliances including an upright cleaner which was a bit like gastric model and an all bakelite hand cleaner, washing machines, hair dryers, etc.
Earlier Dudley cylinder vacs were identical to yours except that the flex was thick and braided and the body covering was in a dark brown fake crocodile skin.the cases were darker in finish and more substantial.
Hopes this helps,
Regards, Walter, Shropshire.