Tucked away at a small institution in Chicago is an eye-opening show by beloved New York artist Martin Wong, a self-taught artist of Chinese-American descent who recorded a bombed-out Lower East Side and heroized his Asian and Latino contemporaries who lived there. “Martin Wong: Chinatown USA,” at Wrightwood 659, also happens to include 11 never-before-exhibited paintings—a dozen if you include the never-before-seen back side of one large canvas. It’s a rare treat for lovers of the artist’s work.  The first monographic Wong institutional show in almost a decade features over 100 paintings, sculptures, drawings, and photographs. It focuses on Wong’s investigations into the two Chinatowns he knew: San Francisco’s, where he was raised, and New York, where he lived from 1978 to 1994. One painting depicts in duplicate the distinctive pagoda-style building at 241 Canal Street in New York, while others represent pop icons like Bruce Lee and Peking opera performer Mei Lanfang. Cultural events like Chinese New Year parades come in for consideration, as do communities beloved to Wong, like graffiti painters and Puerto …