“MAKE sure you mention me in your article,” says the ticket lady at Enfield Chase, a modest station on the suburban line from London’s Moorgate to Stevenage. “I’m Grace. ‘Amazing Grace’, they call me. And she is indeed part of an amazing army of super-knowledgable people who issue tickets on our railways. Want the cheapest ticket and the time of the train from Wick to Whitby on a Bank Holiday morning? Well folk like Grace will be able to help …