William III Half penny??? [solved]

Another Oxfam Exeter donation! I have what appears to be a worn William III half penny

7.16 gm 28 mm

but the date looks like 173? which would make it George II, but he's facing the wrong way for that, and the III seems unambiguous.

Your help is always invaluable and helps me get the best prices for Oxfam:

 On top left of portrait looks like IVS ending, 

so must be GEORGIVS lettering. Date looks like 1770 maybe. 

N#5335 

 For comparison 

 To me the 173? looks more like 17?0 perhaps. 

Ok thanks for all the help. Thi seems right that it's a George III half penny. I'd just priced a William III half penny and got fixated on that!!