This pair shows a change in design following the acquisition by Greenall, Whitley and Co Ltd of Warrington. The label on the left includes the Burton on Trent address; Magee’s brewed there in the former Bell’s Brewery from 1902 to 1904. The one on the right dates from 1959 when Magee’s joined the Greenall Whitley group, whilst continuing to brew in Bolton. I do not believe that design lasted for 55 years! Perhaps there is another explanation.