I photographed this from the in-house magazine, Chance Comments, July 1951, but would your brother mind sending me a proper scan?
Your grandfather must then have worked for WE Chance Co. Ltd, which was responsible for blowing the globes. I did have one until recently, but flogged it! The Chance ones are much harder to find - normally they are Hailware (Hailwood & Ackroyd) and a few are known from Webb's if my memory serves me right (rather less so these days!) Fiestaware was also made by WEC, up to about 1970.