You need to grind out and fiberglass
all of the stress fractures. If you just put filler on them they will reappear and you will waste a lot of time and money
. Dish them out with a grinder enough for a little piece of 10 oz. cloth followed by a couple of matts. You can rip the matt to fit and then roll it out flush on the repair surface for a pretty fair glass repair. Do all of the stress fractures like this at once, and then either do spot gelcoat repairs
if there aren't too many or repaint the entire cockpit if you have lots.