2 more coats of primer...
Id like to use the primer coats to try and get the surface as smooth as i can before the black undercoat, so i may end up putting 6 - 8 coats on depending on how much sanding i have to do.
Will still use a surface filler, an oil based dutch filler, but will be just before the final primer coats. i really want a heavy build up of coats.