ronnie them bumps were air pockets when there rolled the fibre glass they didn't roll it properly you see that alot when you sand it back the heat from sanding bring them to the top which leaves cavities same happy if when mopping the heat bring them cavities to the top pain in the bum just a case these guys who rolled it didn't do the job properly!
ronnie ive worked with gel coat and fibre glass for many years its from going through the grades of sanding then wet sanding then a good mopping but making sure you don't get it too hot.
hope when you get yours reworked it comes out nice
you deserve it from all the work you have done.
as you can see from mine the gel coat as been mixed with white so there are not just black.