So I think those cracks are a pretty easy fix and if you can pick up that top for short money, go for it. Fiberglass is pretty easy. You can't really screw up, worst case you are not efficient in your layups and have to repeat steps. I learned chopping and modding boats by trial and error.
Grind the cracks out. You want a 'v' profile. The longer the scarf (wider the 'v'), the better. You don't have enough grinding where you are into tyvek suit territory, but do wear a mask, gloves, and long sleeve shirt.
You can use the resin of choice; epoxy will give you the best bond, vinylester next, but even polyester will be adequate.
Get some chopped strand mat, pull it apart/loosen it, and use that with your resin to fill the cracks. You want to overlap onto good solid glass and you want 'more glass and less resin' as you do it.
Sand it down. Repeat prior step if there is not enough filling material. Fair with the compound of choice; being you are in LA there have to be some marine stores around, no? They can help steer you regarding these three items.
Once sanded and fair, you are ready for paint.
Some of the stuff listed above is just fillers. You want strength and a good mechanical bond.