Antler is a lot harder then wood. Look on the site for scales that are properly sized to use as grips. A band saw, drill press, fine files, and a belt sander/polisher makes it a lot easier, but hand tools will work, just a lot more labor intensive. Minimize your surface sanding/polishing if you like a lot of bark, instead taking material from the "gun side" to reach proper thickness. Sanding the outside surface can remove a lot of bark, giving the grips an ivory like look. Really, its mostly by feel. Get a block of cheap soft wood, and make a set...That will give you an idea where you are going with the stag material.
Larry