I own a Handi Rifle in 35 Whelen, it has harvested several deer, like the rifle. Like many others here I do prefer walnut to synthetic furniture so I shall endeavor to build my own. Not my first stock, but I'm no expert either, working with tools at hand. The beginning.
Guess I wasn't exactly truthful in the op, I started with a crotch leftover from a walnut logging operation. I was able to scarf up a few of those, all I could do to load those monsters.
Drill the stock bolt hole, dummy-out a piece of all-thread rod in the action, soot the action, slide the stock down the rod, tappy-tap-tap on the butt, remove the black spot, repeat.
HAH!!! I thought about making a smart-azz comment about you being a mechanic and probably going to be the first person in history to use Permatex Prussian blue paste to do stock work, but didn't want to rib you too much. I should have! Good tip, though, I haven't tried it but did try Dykem and it either dries too fast or runs everywhere you don't want it.
Don't laugh, lipstick does in a pinch too.....I said don't laugh!
I have a small bottle of black goo I bought from Brownell's at least 40 years ago. I still have half of it. A little bit goes a long way. I dislike using it.