First, be prepared to have to sand the old ones off. I just tried to get mine off a 1996 Marlin 30 through conventional methods (the 3M eraser wheel and Rapid Remove), and it was a no-go. The blue layer of the vinyl came off with either, but the underlying adhesive layer didn't. I got my 800 grit sandpaper today, and will be trying that this weekend.
Second, I got some from OJs Locker on eBay. They are printed on rectangular clear vinyl. They are not cut vinyl like the originals. Granted, they will look 100% better than what I had (see below). But... they are a textured vinyl, not the smooth vinyl that was OEM. They will look fine, when new, but I am not sure what will happen with the "pits," once you try to wax or compound around them down the road. Nor, am I sure how they will look a few more years down the road, if the fiberglass around it fades.
My recommendation would be to look for something that is contour cut on smooth calendared vinyl.