What a fab box - I can see why you fell for it.
There seems to be a lot of decorated glassware from this period - mainly transfer-printed, gilded or frosted - which was sold without any branding on the boxes. I think one clue is on the box: "decorated in UK", which to me implies that the glasses themselves were probably made somewhere else. France has to be one strong possibility - lots of tableware production exported to the UK at this time.