Good evening, I've been given this coin from a customer who 4 years ago unblocked a drainage trench near where we live.( St Fagans castle) Cardiff . Due to his wise curiosity checked every spadeful of mud that emerged and out popped this coin. I've checked Colin cookes website and I've managed to make out that it's : year could be 1698, Weighs 9.31g Can see a full stop after the(S') Obverse reads - GVLIELMVS TERTIVS' Reverse-corroded but BRITAN ?NIA is possible to make out. Year 10% what I see is 1698 not sure. Could any body shed some light on which variety it is there are so many 1698-1699.