After 28 years of feeding and entertaining customers from across the city and around the world, the duo behind a beloved Sheepshead Bay mainstay — Jay & Lloyd’s Kosher Deli & Family Restaurant — have closed their doors as the pair packs up their wealth of memories on Avenue U.  “There are probably 100 stories, I can’t say how many stories there are,” said co-owner Lloyd Lederman. “I keep looking back and there were only good times — it’s what’s helping me get through this.”  Lederman and his partner Jay Stern have known each other since they were kids growing…