Interarms Mauser, Brown Precision Stock, 20" Douglas Barrel, 3 Position Safety, Canjar Trigger. Express Sights, .375 H&H, about 40 years old now.
Works great, but what I've learned along the way is doing it today the Pre-64 Model 70 would get the nod. Maybe a Jewel trigger, I'd lose the express sights. Muzzle break, Bartlein Carbon Fiber barrel, or fluted. I'd get a 1-9" twist to handle every bullet out there today. I'd go with a Mcmillan Stock, probably a Lazzeroni Thumbhole I have one I really like on another rifle. Probably target 9lbs scoped, 10-12 is just a little on the slow side for fast work.
Consider the Weatherby, or AI version, and you can always use the H&H rounds in a pinch, and a bit more pep with heavy bullets, and enough velocity improvement to add some range for plains game etc.
I looked at the Defiant, 3 position safety CRF, and that looks like an excellent starting point as well. It might make me give up on the Model 70.
Good Luck!