Smooth edge or smoothed? These were struck without a collar and had a diagonal milled edge. Filed down edges and made round could be due to making it fit jewellery or something. Any trace of a mount on the edge? If it looks like it was originally struck in a collar, then it's a dodgy one. The missing 17 isn't something I would worry about. A full date is nice, but you do get weak characters at random places in the legend from time to time.
 
	It doesn't look right though.