identification of ale glass

/sites/default/files/pictures/medium_CIMG4732.JPGHi thereI was hoping someone could help me I recently purchased this ale glass and am having trouble dating it.  It measures 175mm in height, the top of the bowl measures 120mm, the knop is 45mm in diameter and the foot is 90mm in diameter.  It has a rough pontil mark below the foot.  The interior of the glass is cloudy and there are plenty of scratches.  In low light the glass turns a silery, grey colour and is quite heavy.  It also has a very good ring to it when tapped.Any help most welcome ChrisI have attached link for photos hopefully i have manged to do it properly.