Your pics are good and show the details well.
I would call this an Ale glass rather than a Gin, as the Funnel bowl would seem to be larger than for a Gin glass - unless the whole thing is not very tall.
As far as I can see the proportions and the overall look seem to be ok for 18th century, and probably English. With a folded foot it would normally be dated to up to about 1740. However, without a knowledgeable person handling the glass to check the actual look and feel of all parts, as well as the weight, and maybe the UV fluorescence too, we should not assume a 100% attribution here.