I got the seized piston freed from my twink and took the engine in to Bill McCurdy (Williams Racing) for evaluation. Bill says that, because of the corrosion from the seized piston, the bores will need to be honed 5 or 10 thousandths over, and thus will need oversized pistons, but he says all that's available new are standard-sized pistons. So he's recommending custom forged pistons. Big bucks.
Anyone have a set of decent oversized pistons lying around?
--Rob (still a total noob)