Painting the body proved to be quite a nuisance. After smoothing the surface with the finest sandpaper I applied spray-on base coat.
However, when the first layer of paint dried it developed a brittle surface.
I probably didn't let the paint dry long enough or too long. Removing the paint and adding several layers of it in a few minutes' intervals did the trick and yielded a smooth surface. Finally, I applied a few layers of glossy clear coat to make it durable, which I then polished with Carnauba wax.
The pickguard painting was straight forward without any issues and it also received a clear coat finish.