Ed: chequering a wrist like this is not too much different than any other chequering job. But notice that the "diamonds" are almost square and flat topped rather than elongated to 2 1/2 - 3 to one ratio, and pointed, like modern chequering.
I start with some 1/4" wide plastic strips, laying one along the wrist and taping down the ends. Then a sharp scribe is used to trace a line into the finish - yes, the rifle is completely finished before chequering begins. Once one base line is scratched in, I remove the strip and tape it down to the wrist going in the other direction in this case, at ninety degrees to the first line, to create the angle of intersection I'm looking for. In the case of my Kuntz rifle, the strip had to go completely over the wrist and onto the opposite side of the stock. Make sure the ends of both lines end up at the same adjacent spot on opposite sides of the wrist. Once both layout lines at scribed, I cut them with a parting tool. Now I have solid layout lines that my cutters can follow without slipping out of the groove and creating a mess.
I use DemBart and Gunline chequering cutters that are 60 degrees rather than 90 degrees. In this case the lines per inch were 20 iirc. The cutters have a smooth side parallel to the cutter side. The smooth side rides along in the groove you've cut with the parting tool, and cuts a parallel line to than groove. Take the line right up to the border of your pattern, but don't try to finish it at the border. Continue following cut lines and creating new lines until your entire area within the borders is cut - all lines going in the same direction. And don't try to go to full depth with the first pass.
Now cut all the lines following the other lay-out line, which will give you the chequering pattern you're looking for. I take the lines to within 1/16" - 3/32" of the border lines. Once the entire wrist is chequered with one pass, go back to the beginning and re-trace your first cuts, deepening the lines. Again, finish all of the lines that run parallel until the entire wrist is cut twice in one direction, and then follow the other set of lines deepening them. I usually have to cut all the lines at least three times before I'm satisfied that the pattern is deep enough.
Turn out all your shop lights except for one incandescent bulb over your bench, while you do your cutting. The shadows from the lines will make it easier for you to follow than if you have a brightly lit shop.
I use a 60 degree parting tool to finish the chequering right up to the border lines, and also a cutter that has the teeth reversed so that it cuts on the pull rather than the push. This way, you can set the cutter right in the groove at the border line, and pull the cutter toward yourself, finishing up the line without danger of a run-over.
This has been a very short treatise on chequering with a great deal not mentioned, but it should get you started.
Oh yes, finishing...once you are satisfied that you have cut your pattern as deeply as you want, and you're done, use a toothbrush to clean the chequering, removing all dust. In fact the brush is used frequently to make sure dust doesn't accumulate and blur your work, and clog your cutters. Apply stock finish with another toothbrush, sparingly and thoroughly, wiping away any that goes over onto the finished wood. Apply several applications drying between, to seal the chequering lines.
In the case of a half-stocked rifle, use a chequering cradle to hole the stock. Then you can use two hands to run and guide the cutter and the cradle holds the stock firmly. I made my cradle out of scrap maple using a pattern from a gunsmithing book called, "The Modern Gunsmith". I clamp my cradle in a machinist's vise. For this rifle though, the cradle wasn't long enough, so I just held it with my right hand in my lap, and chequered with my left.
I'm sorry I don't have pictures of all this...I have posted this information here before , in the thread involving the pistol gripped Hawken rifle I built a few years ago.
