If no one comes up with a good answer, here is what I would do.
I would say that it should be spray painted for the best looking job. Any automotive paint shop could tell you what is needed to paint fiber glass. But of course auto paint has to be sprayed. A good paint store not WalMart or similar places, these places have sales people and they know very little about paint. A good paint store where they are knowledgeable should know if there is a roll on paint that could be used. I assume this might be what you are looking for.
Depending on the width of the spider cracks paint probably won't hide them, many years ago cracks in auto paint were filled by using primer on a rubber scraper, you scrap the primer into the crack so that only the crack is filled and none is left on the surface.
Also search the internet, you should find information on painting fiber glass.
The decals might be able to be bought from JR Repair.