Tony and Oscar winner Mercedes Ruehl has signed on for Second Stage Theatre’s fall revival of Harvey Fierstein’s landmark dramedy Torch Song. Michael Urie will star as looking-for-love gay drag artist Arnold Beckoff, the role originated by Fierstein, which ran more than 1,200 performances in the 1980s and earned Fierstein Tony Awards as best play author and star. Ruehl (The Fisher King, Lost In Yonkers) will play Arnold’s mother, a role taken by Anne Bancroft in the 1988…