IMO, it the stock has a crack in it, stripping, sanding and refinishing it won't change a thing.
About the best thing you can do is to keep the crack from growing larger.
I'm guessing the crack is in a thin area like along the barrel channel or someplace like that.
If you can get at the crack from the inside surface where it won't show, you might be able to open the crack a little.
If you can open it a bit with a very sharp knife so that you can get some glue down into the crack you will be able to stop the crack from growing.
To make some glue that will work, get some of the yellowish carpenters glue. Pour a little bit into a small paper cup and thin it with water (about 60% glue and 40% water.) Then work this thinned glue down into the crack, remove the knife (or whatever) and close the crack with a clamp (or rubber bands) until the glue has set.
Another glue that will work is some of the watery magic glue. Work it into the crack from the non visible side and clamp it up for 30 seconds.
zonie