Fretboard finishing

Hello everyone,

I was stuck on something. Im using black walnut for the neck/fretboard and wondered, do I lacquer the actual fretboard surface or just apply something like lemon oil as I would on a guitar? I cant see how I could lacquer it with the frets installed, and trying to install the frets after it had been glued to the rest of the instrument and lacquered seems like a recipe for disaster. What does everyone else do?

Thanks,

Iain Craig