If your going down the Pope method, experiment on some scrap first, not the bow.
I have found plain old shellac(or blonde depending upon the colour of the wood) dissolved in alcohol, to be quick, effective, and easy to apply. For the first couple of coats I put on are pretty thick. Steel wool between coats. Further coats are from a more diluted solution, it helps them blend into the subsequent coats and helps to stop runs from happening.
Shellac was found by Dean Torges to be one of the most effective finishes for keeping out moisture(more so than modern varnishes).
As to durability, it is pretty good, better than many give it credit for. It can easily be touched up.