NEW YORK (REUTERS).- Steve Martin glides from acting to music to writing so fluidly that he gives the impression it all comes easily to him. Martin admits “a certain kind of ease” with writing fiction, as exemplified in his new novel “An Object of Beauty” from Grand Central Publishing, but only now does he feel that way, at age 65, years removed from the “wild and crazy guy” who burst into show business as a stand-up comedian in the 1970s. “Object of Beauty,” which hit bookstores on Tuesday, tells the story of an alluring and ambitious art dealer named Lacey Yeager who climbs from the basement at Sotheby’s auction house to open her own gallery in the Chelsea section of New York. “If I had tried to write it 20 years ago, I would have suffered. I suffered a long