love the hull lines
on these boats.
sure, rough it up inside and put a thick layer of mat in there, then on the outside, sand about three inches around the crack past just past the gray to pure glass. then, sand an oval about four inches beyond your first grind into the gray. paint
some resin into the crack and let it cure overnite. thensand smooth and apply apiece of mat over the area you ground past the gray. again, let cure overnite, and once again sand smooth. i suggest a variable speed feathering sander for optimum blending. now apply cloth over the area you cut into the gray. let cure, sand smooth, and you should be setting pretty. fill any imperfections with short hair bondo.
now as far as rigging
, there are some differences as yours is a raised deck model. have you checked out the columbia yacht owners association websight? there's a lot of challengers in the owners registry. you may do better trying to contact a challenger owner for more info. most people are more than happy to help......