Nicholas Howey, Kenneth Gentry and Dallet Norris -- the triumvirate that runs the Harlequin Dinner Theater in Rockville -- have just formed Prism Productions, Inc., with a view to mounting "Finian's Rainbow" for Broadway. The musical by Burton Lane and E.Y. Harburg first hit New York in 1947 and ran for 725 performances, but hasn't had a major open-ended Broadway revival since then. Ray Bolger has been contracted to play Finian, the whimsical Irishman who borrows a pot of gold from a leprechaun and brings it to America to bury in the soil so it will multiply. Howey says "we're talking to Richard Thomas" for the role of Og, the leprechaun, originally played by David Wayne. Burt Shevelove, who spruced up "No, No Nanette" for our times, is being mentioned as the director.

The revival will be capitalized at $1,750,000, which Prism Productions hopes to raise both here and in New York. Howey says he's planning to go into rehearsal next summer with a New York opening in the fall. His pitch: the times are once again ripe for the show, which looked imaginatively at a period of economic uncertainy in America, poked fun at the "idle rich," and spoofed the notion of unbounded credit.