It looks OK in the end: for the Veuden ships I'll probably go with a brighter grey hull while keeping the white superstructure. I might also add a rusty wash to the superstructure.
The whites are going to need standard treatment (instead of 2-3 successive layers) and the ships must be undercoated white because this black does not yield the colors I would have liked.
On any further ships both ends will need a lot of careful sanding as obviously this is where the grain of the wood shows through.
The casemate gun ports are pieces of paper fixed with PVA.
An acceptable result in the end, with the desire to do better, I'm working on a Jackewlinese cruiser now and things go more smoothly.
In other news, as I wrote in a reply I took out a fresh scalpel blade (the previous one was being used for quite a while) and with the 2nd cut I managed to have it slide down the piece of wood I was working on, along my right thumb down to the palm (perks of being a lefty), a necessary sacrifice for SCIENCE. Plus it's only surface damage and my right hand is full of various scars already from hobby works.