Your photos don't show anything that needs a primer with fillers. Those reflections are "fair" as they say in the boat shops.
And I like the black. If there IS an undulation somewhere it'll disguise it all the more as a second seat. (You could paint faux quilt stitches on top.)
"The belief that there is only one truth, and that oneself is in possession of it, is the root of all evil in the world."-- Max Born, Nobel Physicist