I went to the painting & home decor shop and bought some 1000 grit sandpaper. Proper tools and methods ease working on these ships a lot. I'm getting the knack of it now, so here are a pair of cruisers, Veudeni on the left and Jackewlinese on the right - as I'm not planning to add flags the distinct hull colour was an obvious choice, bright grey/white vs. black. The paint jobs are, as opposed to the first pre-dreadnought, just two or three similar layers over a white basecoat. For the white ships I'm still considering adding a thin wash.
I sort of tried to hinder the modern look by using classic paint schemes, and I have to admit this looks much better than sea gray.
Here's an assembled hull for the 2nd Veudeni ship, the trick for a smooth surface is sanding a lot and adding PVA between each sanding, after two or three times it's going to be really nice. I sanded & PVAd the two pieces separately twice and then a third time when they were glued together. Sounds like a tedious process but besides this, adding superstructures and painting the thing takes very little time. The PVA also acts as a varnish and protects the wood. I didn't even add a finish to the cruisers. This battleship will have a very French and thus a more antique look compared to the ones before it.