Stuart - nice glass - forgive me for being Mr. Picky

Having just swotted up on annulated knops, I'm getting the impression from my books that correctly this type of knop should consist of an odd number of discs and be symmetrical in appearance - although this one does appear to have the six discs that you mention.
Annulated knops seem to have been popular in the first half of the C18 - so is your reason for dating this to the early C19 due to the presence of what appears to be a bladed knop?
I'm not suggesting this glass is earlier than you are saying, but just a few thoughts in passing.
Assume you mean a snapped pontil?
