Need some help. I'm fixin to repaint my huntin wagon - 76' Chalet - and ordered in a gallon each of od green and flat black from Rapco Parts. I've got no experience. Anyway, I'm going to clean well with mineral spirits, then scuff it up with some 120 grit. I pick up a lot of brush scratches when I'm out and about, so I ordered a couple of spray cans each of the same color so I can touch it up as needed. Do I need to prime and can I use the same primer on the metal and fiberglass? Also, gonna go with od green truck, black camper with a green top on it. I'd welcome any opinions on that also.