Before painting, there were quite a few pinholes in the hull to be dealt with. While tiny, they would ruin the finished model and once paint starts to happen, it's too late to do anything about them.
As I've mentioned before, I'm hopeless with filler, the best I find is Deluxe Materials Perfect Plastic Putty. This was smeared over the holes, trying to keep the layer as thin as possible, and then left overnight to harden.
Excess "putty" was removed using abrasive sticks and I was pleased how tidily the end result looks. A coarse stick did most of the work but I finished up with something much finer to avoid scratches in the smooth hull sides.