Whilst clearing out a display cabinet, my wife commented on the fact that two Sowerby(?) High Level Bridge mugs were different. I hadn't noticed, but on looking closer I saw what she meant. One has straight vertical sides, whilst the other has a slight fluting outwards towards the top. This cannot be an after treatment after the mug had been taken out of the mould, but looks as if it is a different mould. See attached photos.
I just wondered if anyone knew of this difference or anything about it, and whether the straight or fluted mould is the most common?
Michael.