Like many other cruisers, I keep the sole covered with indoor-outdoor carpet. A varnished cabin sole is TOO DANGEROUS when underway in any moderate seaway, especially when it gets wet. And it WILL get wet!
Having said that, you may want to check out a product at:
A test of this was done by a professional yacht refinisher at:
For the rest of the interior it''s one of those ''labors of love'' to get a smooth finish. Many layers with wet-sanding in between gives the best, though laborious, result. And don''t be afraid to spray the final coats ... I have varnished surfaces on the interior that were done 10 years ago and you can still see your reflection in them!
You can see some of this at:
Good luck with the project.