In Old Towne Orange — a mile-square district established during the citrus boom of the late 19th century — reverence for the past is part of daily business. At the center is Plaza Square, where cars whip around the Victorian-era fountain and garden in a traffic circle once trod by horses and buggies. Around the plaza, old-fashioned soda fountains, barber shops and historic buildings mix with trendy fashion retailers and wine-tasting salons. It’s not surprising that Old Towne Orange has been dubbed the “Antique Capital of California,” with antique depots crowding the district…