A marine Tung oil would work nicely. It's water resistant, pops the grain of the wood, and you can wet sand with it to fill the pores making a nice smooth flat surface. Then you can leave as is, and a few coats of wax, or apply a wipe on poly or gunstock finish, the choices are pretty broad. Make sure to check to see if the finish will dry clear, or add its own flavor. You may apply something, and it can change the color of the lighter woods. I.E. amber shellac will add a yellowish/blonde hue to lighter woods, but natural shellac will dry clear as day. Hope that helps.