I would remove the base if possible and not take a chance of damaging the boat or soaking a penetrating solvent into the interior. Dad used some stuff for years called marvel mystery oil. Looked like trans fluid to me. He used to thin it with something and use that for rusted hardware. The atf/acetone mixture is the first time I've heard of something like that in years. Like everyone sez, great info out here, Y'all are the best.
Wake me up early,
Be good to my dogs,
and teach my children to pray.