One thing with a Poly finish, if you thin the poly 50% for the first couple of coats it absorbs into the wood. Then finish your top coat as normal creating more depth to a finish and harder to scratch into the wood. Another trick is shoot your base color then mix 50% clear on a 3rd coat with a clear top coat. That makes for an extreem depth in appearance. Lots of tricks if you have time, and one last trick Auto paint suppliers can mix a custom color and put in a spray can for you. That way your not stuck with the old Nitrocellulose finish.