Engine Room gray gelcoat restoration

i am looking to restore the gray gelcoat in the engine room. I have places where chunks have come off, where it is stained and where there are significant cracks. What's the best process? Should I fill the cracks and missing chunks with an epoxy (or with a gelcoat?) and then paint with gray bilge paint (I didn't see grey gelcoat anywhere on Spectrums site)? How do I best prepare the waxy gelcoat to accept paint? Sand and solvent?

I’ve had good luck with interlux bilgekote they also make a pre-kote primer you may want to use. The o my downside is it takes about 48 hours for the stuff to dry completely.

We took a bunch of swatches from Lowes and matched it exactly. We had them mix up a gallon of their oil based paint that color.

Ken