Hi, any help with an attribution - an educated guess will do - greatly appreciated

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Has the flame pontil mark ( flame on the left hand side ).
I understand however that Kerry Glass and St John's Glass also used the flame pontil mark - hence
my uncertainty!
It's only about 5cm high.
For what it's worth, my uneducated guess would be that it's IOWSG - based on its colours.
Thanks for looking.
Scott