Chris,
Get yourself a corded Dremmel tool, cordless hasn't enough ass for woodworking in my opinion. The Big Shot grip has some tits left on it where it was held by when the carving was done. The pantograph, I'll call it that for lack of a better word, has a rotating round nose cutter which leaves fine paralell groves in the wood. These aren't real deep at all and are only in certain contours of the grip. With a Dremmel tool and a sanding disc attached, these groves can be worked out nicely. The fit to the frame needs no attention. I have all the necessary shop tools so it wasn't an issue for me but you can improvise. A sanding drum chucked in a hand drill will work nicely if you clamp it in a vise. I started out using a Black and Decker Workmate to hold a belt sander, orbital sander, hand drill, etc. Gunstocks Inc. will carve anything you send them into whatever configuration they offer. Richard's Micro-Fit sells blanks of laminated material for a reasonable fee and they have some colors that aren't usually found as finished stocks/grips. If you choose this route, contact Gunstocks Inc. to see what size is required for your stock so they have enough surplus material to hold it by when carving. I would like to get a nice thumbhole in a Timber camo but I have so many projects started that I need to finish first. Good luck.