Hunter20ga is right, TQ: the best thing about oil-finished stocks is that all it takes to get them looking like new is another coat of oil--be it teak, or linseed, or some other combination. Whereas a lacquer, varnish, or uerethane coating will eventually chip or peel and necessitate a total stripping and recoating, oil is designed to be easily rejuvenated as often as one wants. One caveat: always apply this oil topcoat very sparingly--especially if it's linseed oil. It's often best to thin this topcoat, too. If you put too much on or it's too thick or you do not remove all the excess immediately, you will ultimately end up with a gummy, dull, dark finish.
I like to hit my oiled stocks about once a year with a very light coat of 75% linseed/25% turpentine, warmed to about 150 degrees in a double boiler. I rub it on--and we're only talking a few drops per side of a buttstock and a few more for a forearm--wipe off any wet excess after five or so minutes, and then immediately buff it with a soft cloth until the surface is absolutely dry. This is just enough to replenish the oil that's in the wood and reseal the uppermost layer to a watertight, glowing sheen. You'll see any light scratches disappear, too.