Photographs and one particularly interesting artifact — a ledger showing expenses from 1953 — helped tell the story of Northeast Georgia Diagnostic Clinic’s 60 years in Gainesville. But nothing quite conveyed the history like the ones who lived through those years, including founding physician Dr. Henry Jennings, who gathered Monday for an anniversary celebration and luncheon. “Time passes fast,” said Jennings, who cut the first slice from a white-icing cake baked for the occasion.