This is wonderful !!
Your hat Paul looks like the colour of hat 1 on the far left under the glass hat search !!
The second hat in looks like it has a folded rim.....which is good news !
I can't see anything like mine there but I think mine is bottle glass and yours Paul could well be window glass (from Nailsea, what a great find if it is !!)..... mine might be from one of the bottle works in Bristol or Nailsea (perhaps) ..... I will just have to try and match the colour but as the greens varied so much even that will be difficult to prove. At this point all I can say of mine is that it has age, it was bought in the region, it's of a bottle green colour and has a half-folded rim

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The other green hat I had of the same colour (mentioned above) had a sharp pontil snap , not fired like this example. It might be an easy matter just to stick the hat under some heat though to smooth the finish. Perhaps this was done in the bottle making process where a seperate souce of heat was to hand.
The other hat, I had sold on ebay for £30.00 and was bought by an American gentleman.....oh how I wish I had kept it

For me it's not the value of the hat that matters it's owning a piece of local glass history which would be nice to prove ! .....However , that might be too difficult.
I'm very pleased about the colour match with yours though Paul it looks very promising indeed !!
Thanks so much for all the comments everyone ....it's great !