Spotted in a charity shop for £2 seemed worth the risk.
It's 24 cms high, with a concave pontil mark. the bubbles stretch out the further they are from the base. The base has quite a bit of wear. I've hunted the net for info, but got nowhere - does anyone have any useful pointers please?

and a tankard I picked up in the same place.. 15 cms high - similar pontil.

Many thanks
Steve