You’d think it might have occurred to somebody that a solid gold Caddy would make a pretty unwieldy vehicle. But you can understand the temptation: A suddenly timely ’50s farce about an out-of-work actress who brings down the fat-cat board of America’s biggest company with what starts as a few pointed questions about executive compensation? Starring that dingbat diva, Nancy Robinette? It must have sounded like just the thing to goose the December box office, so you can forgive the Studio Theatre for billing it as a “lost American classic.” Look further than the marketing language, and what you’ll find is a wan, second-rate farce from George S. Kaufman, whose collaborations with Moss Hart are justifiably celebrated, and Howard Teichmann, whose collaborations with all and sundry have heretofore gone largely unremarked. Loose of plot, thin of character, and mild in its scorn for the corporate cluelessness it sends up, The Solid Gold Cadillac was conceived as a vehicle for the grandmotherly character actress Josephine Hull, whose signature brand of dottiness can still be appreciated in the film of Harvey, for which Hull took home an Oscar just a couple of years before she stooped to this clunker. For Hollywood, the play was reinvented as a showcase for Judy Holliday, who’d more or less patented a sexier brand of trouble-making scatterbrain with Born Yesterday in the late ’40s. In both incarnations, it was received as a “graceless random satire” (that’s Brooks Atkinson, reviewing the original in The New York Times) or at best as a “cardboard farce” (Bosley Crowther on the film) in need of deft direction and a focused star turn to stay between the lines. Neither is in evidence on 14th Street: The pace is slack enough in Paul Mullins’ production to be actively fatiguing, and the director doesn’t seem to have done anything to focus Robinette’s comic creativity on who her character is and what she’s up to at any given point. A game ensemble supports her where they can (Leo Erickson and Paul L. Nolan do particularly nice work as corporate officers who’d clearly sell each other cheap), and for brief moments you catch glimpses of the kind of pointed character comedy that might’ve emerged with more thought. Without it, and without a stronger hand at the helm, an actress who’s arguably the city’s most gifted purveyor of the double-take is left to faff about in every direction, and to correspondingly little effect.