Dear Jac: Coins of the realm, but which ones are bona fide?

Time to talk money. I was contacted by Binz Sidhu, who owns a small shop in High Ercall, at Telford in Shropshire. He took over from his parents last October and says he’s been baffled by the not-quite-the-full-ticket coins that have come across his counter ever since. “I’ve noticed that ...