Rubbing down the edge of the primer with white spirit before it was set hard worked well. No noticeable edge to the painted patch. I have applied a single top coat and I am pleased with the result. There is a very slight undulation, but as I mentioned earlier, that is the case with the hull in many areas. I will rub down the very slight raised edge later. I will then overcoat the whole hull at a later stage.
I have also roughed out a support base to two interior lights. Once that is painted I will fix it in place and if it all works, that will be the interior electrics completed. And it isn't even November yet!