Nice progress Jen (& Dad)!
if you haven't already got to the pinholes, here's my thought.
i wouldn't use the
fiberglass resin. You don't want to use something to fill the holes with that's harder then the primer- and it is. Thre's a polyester filler that's just like bondo but very smooth. It's used for imperfections right before the sealer before the
paint. I have some but it's out in my shop and it's a Louisianaraining right now. It's made by Evercoat and there's probably other brands, too. Available at the same place you buy your
paint. Easily sandable and 2-part, it won't shrink on you after you paint.
Also, you don't have to seal it for small holes, it just seems like everybody uses sealer these days.
Most primers are primer/sealers. If you reduce it a little more it becomes a sealer. If your silver is a metalic silver, sealing right before
painting is a good idea.
Also, if you are
painting it where it is (on the concrete), wet the floor and bolt a chain (or wire) to the frame. Let the chain lay in the water for an earth ground. It helps the metalic in the color lay right.
Even with the body being
fiberglass, static elctricity will build up and cause "splotchy" or cloudy areas.
If your dad aleady knows this stuff, sorry. It may help others, though.