There should be a whole new word for “disheveled” to describe Jeff McCarthy in Kunstler. As William Kunstler in Jeffrey Sweet’s one-act snapshot of the liberal 20th-century lawyer, McCarthy looks terrible, sporting un-manicured sideburns, messy gray hair with Poindexter eyeglasses nestled in it, an awful tie, and a suit that looks like it was rolled around in dirt before curtain. The look reinforces that this legal near-icon wasn’t into appearances, and it jibes nicely with the shambling, authority-challenging portrait McCarthy and Sweet paint. After a strong beginning, Kunstler settles down into wandering monologue, and leaves some vital questions about its subject insufficiently answered. Still, this Kunstler-at-law is lively company.