The shape book indicates two size variants, 63-6 and 63-10.
Shape book 'A'
63-10
This number is rare or perhaps non-existent. There is no example in the image database. The shape book, although listing it, leaves the dimensions blank. A 1950 photograph of the wall pocket range by wholesale agents Burmatt does not show it, just 63-6. The -10 suffix would imply a height of 10 inches (25 cm)