I did a repair very similar to this on a 5.2 of '76 vintage.
First, I placed an inspection port on top side - note - cut the hole for the port, but do not put port in place till after all the bottom side work - you'll have a bigger hole to work in, and you won't gum up the new port.
I cut out the damaged area & feathered the edges.
I made an outside mold - low tech - waxpaper & tape. Then made one thin glass/resin layer on inside of hull, working through the porthole.
Then took off "mold", and finished up the outside with another layer or 2 of glass/resin, and painted. It was very strong, and no more weight than original. Fiberglass work is very easy, if you use good materials, and aren't obsessed with weight or beauty.

Hull cradles - are very nice, but in my opinion, are not required to be as curved. I just use a 24" piece of 2x6 under each hull at each roller. The length of the board is aligned with hull, I have small cross-pieces on the bottom of the 2x6 to keep it from jumping off the roller. This wood keeps the weight of the boat distributed on a larger area of the hull ( 18-24 sq inches?) than just the intersection of the roller and hull (1 sq inch?).