Which Varnish?
With regards to Which Varnish, Quite a few years ago now I used a product called "Finnigans", it was what you might call a heavy duty type of varnish, thick and sticky. if doing a larger surface you could practically pour it on in a small pool and simply brush it out and it found its own level. As this varnish had an Epoxy content when fully cured you can imagine how hard the finish was and it had a long lasting reflective shine. I would think that with care this varnih would look good on the deck of the model of a 1930s steam launch or speed boat.