Sure. A "resin" wood is basically just wood that's been saturated with plastic. It's like it's been painted with polyester, but all the way through. It's not really any harder than plain wood, but it wears better because the grain is all filled up with the plastic resin.
So yes, you can pull the frets and file it or sand it as if it were a normal piece of wood. It will be messy and smelly because of all of the plastic. When it's leveled and smoothed the way you want it, then you have to polish it back, similar to the way that you'd polish up an epoxy coated fingerboard. But without worrying about going through the epoxy! It's more labor than polishing a bare wood fingerboard, but it's reasonable and you should be able to bring it up to its original gloss.
Fill the slots with wood, sand them level, and then soak them with superglue.
Last edited by Bruce Johnson : 01-20-2013 at 09:39 AM.