If I'm correct, the escutcheons on your rifle will be small ovals, perhaps an inch long and 1/2 - 5/8" high. Since there are eight of them, they will require a commitment of some time and patience, but are very simple to inlet. Be sure to file a 'draft' on the edges while they are flat, and then curve them with a piece of pipe in a hollowed out piece of maple to the contour of the stock. Use the key to hold it in place while you draw around it with a sharp pencil. Withdraw it, and mark it along the top inside edge with a little nick of a file so that it goes back the same way each time. Use a narrow stamping tool, and chisels that have less than the radius of the curves, to cut within those lines. Remove a furrow up to the cut line all the way around the stamped line, almost to the depth of the inlay's thickness. Remove the wood inside the oval first with a 1/4" gouge chisel, cutting across the grain, and then pare away the tops of the ridges with a small flat chisel. With the inlay still on the key, black the inside of the escutcheon and slip the key back into its slot, until the escutcheon contacts. A light tap with a rawhide mallet will transfer the colour to the high spots in the inlet, so you can remove those until the escutcheon bottoms.
You can secure the escutcheon plates with small nails or two screws with just enough countersink to allow the slot in the head to be removed. It takes me about 15 - 20 minutes to inlet such an escutcheon this way...you get better (faster and more accurate) with each successful inlay.
Dremel: a useful tool in the hands of one skilled with this fine work, but a disaster with one little ooops! "Go placidly amid the noise and haste, and remember what peace there is in silence" ..or something to that effect. Enjoy the ride for what it is, and relax with this. Every escutcheon will be an enjoyable challenge, so take your time and savour the moment.