Early English Hammered Or Scottish Gold? Or Fake

interesting coin:

looks like a standard effigy of Geo.II.
1727 was the year he ascended the throne.
The shield looks more like those used by G3 in the 1780s; or like the reverse of sixpences or shillings of 1727.
I haven't yet found a reference to an "S" on coins of that era.

I suspect that you have a gilded 6d or shilling: gilded to be passed off as a half-guinea, etc.

What weight & diameter is this coin please ?

Peter in Darwin.

It's a genuine enough coin, but it's not British. What you've got here is a ducat from the German homeland of the British kings: Brunswick-Luneberg. Listed in Krause as KM# 209 or 210 (there's no pics for these coins in my Krause, and I don't know the difference between these two coins). "S" stands for Christian Philip Spangenberg, mintmaster of Clausthal mint. 3.5 grams is the correct weight for the ducat.

Even in this somewhat abused condition, it's still worth more than bullion value.