As far as I know a touch piece was a gold angel - a king would be unlikely to use silver - its a curency shilling anyway.
I seriously doubt its original as well it just looks "wrong" could just have been badly cleaned - but its in a plastic "Tomb" so you would have to take it out .
I remember seeing a holed example on a maket stall in leek staffs , it was in GVF far superior to your and the vender only wanted a hundred for it , I was broke at the time so I passed on it but it was well worth a hundred.
I hope you never paid much for it ..........Mint mark is a Tun
Stress fracture points to it being genuine though