I think maybe it was a stroke of genius that led Harris to use it in his pieces, what better than something that has the geenish tone of WATER and also includes BUBBLES.

Well my theory has just been blown out of the WATER because Alfred just told me that "Harris and Boffo were not happy with the rubbish glass"......
He was not sure when they stopped using the bottle glass ( maybe that was after he left ) but he mentioned the bottles were replaced with cartons .
The bottle glass also had the addition of glass used for chemistry bottles, very fine.
Alfred tells me he will join the group so hopefully you will have answers ' Straight from the horse's mouth'