I've built a lot of furniture/cabinetry and several dozen guitars, basses, boats, and gun stocks over the years. My screen name here comes from the name of my former business. Philo Custom Shop.
Boats and heavily used/abused furniture get high quality varnish with a paste wax top coat. Guitar bodies and gun stocks get 'true-oil', a polymerized tung oil available from Birchwood-Casey. Fret-boards on the guitar and bass necks get lemon oil or similar.
It's all about what you need the finish to do:
Heavy protection requires a heavy, thick, and durable finish. Fine for canoes and kayaks, and kitchen tables where children are expected (drunken card players fit in here too), but not usually very pretty up close, nor comfortable to the hand.
Guitar bodies and gun stocks are subjected to some abuse by their very purpose, but for the most part they're lovingly cared for after the fact, and in the end they need to feel good in the hand.
Guitar and bass finger-boards have little purpose but to feel good to the hand and to resonate with the rest of the build. That's why only the densest high quality woods are used for fret boards. Ebony, rosewood, and old-growth sugar maple. The finish is there to prevent them from drying out and cracking. This means keeping them oiled with something they will soak up. Certain woods prefer certain oils, to a varying degree, but pure lemon oil is hard to beat.
To answer your question directly VictorViper, I'd keep it oiled and nothing else. A pure lemon oil every couple of days or so. If you want to get fancy there are very pure oils made specifically for guitar fretboards available at most music stores that sell instruments.
It's a beautiful
mod, and with the oil it'll end up with some dings, scratches, and finger marks on it over the years. That's patina, and proof that's it's been with you for a while. A hard finish will probably do more harm than good.