A good way to strip a stock is use some kind of wood "refinisher". Formbys or any other brand. Paint it on, scrub with a soft brush, and wipe off the finish off with a rag soaked in the refinisher (wear gloves) It may take a couple of coats to remove it all. Then raise the grain and "sand" with a scotchbrite, if needed. This method will remove NO wood so everything will fit right. I never use sand paper on a refinish job, that takes off wood and .yopu don't wanr that.....Good luck...Ed
P.S while you are at it take a close look at a few original Hawkens as those GP rifles could use a little "corrective" wood removal, especially the lock panels IMHO....