I guess it depends on whether you're going for "looks like new" or just "working gun okay." I would tend to go for "working gun okay" because the investment of time and effort to attain "looks like new", to me, would drive me to just buy a new set of grips. "Looks like new" would involve completely stripping and refinishing, with steps taken to protect the checkering and being prepared to "freshen up" the checkering if (probably) necessary. For "working gun okay" I would simply and carefully sand the bottom clean (no strippers or other chemicals) and refinish with oil or whatever. (Looks like they were originally lacquer or varnish.) If they are the original stocks, numbered to that gun, I'd do nothing, just take them off, set them aside to go with the gun some day, and get some replacements from Altamont for using the gun.
A lot would depend on the condition of the gun and what I had in mind for it.
