Costanzo’s West Park Barber Shop is a step back in time.The back bar, sinks and mirrors are vintage late 1940s or ’50s. But the proprietor, Fred Costanzo, is not. I was scheduled to meet Fred’s nephew, Santo Jr., at the shop — so when I walked in and saw a good-lookin’ fella with slicked-back black hair lounging in one of the antique barber chairs, I thought it was Santo.I introduced myself and asked his name.“Well, I’m Fred,” he said.“That can’t be,” I told him.