If I were building what you describe for my own use, I would start with a Pre-64 Model 70 .30-'06 action with some extraneous holes in it, one that would have absolutely no interest as a collector's gun. I would have the bolt face opened and have it rebarrelled with a 22" barrel, Lyman 48 receiver sight, ramp front sight with sourdough blade, Griffin & Howe side mount with a Leupold 1.5-5X VariX III scope for those occasions when a scope is needed. McMillan fiberglass stock.

Beat up Model 70 actions can still be had at a reasonable price, and the .458 cartridge was designed to fit that action. Since you will only be using the action, stock and barrel condition are unimportant. 8 pounds is about right. You will never notice the recoil shooting at game.

One of my African rifles matches this description, except that I opted for a wood stock and used the magnum action and the full length .450 Watts. The action was one off a rifle I had acquired from an acquaintance who liked to do his own gunsmithing, in this case rechambering a .375 H&H to an "improved" cartridge. In the process, he increased the headspace to the point that it was .021" excessive. He had also fitted it with an Echo side mount which gripped the scope (a Lyman Alaskan) so poorly that he had to install setscrews to stablize it (and cut notches in the scope tube).

In those bygone days, Lyman would do almost anything to a scope, including, in this case, replacing the tube and reticle at a nominal cost, and Winchester replaced the receiver and barrel of the .375, leaving me with a spare receiver, which became the basis for my .450 Watts. Using a blank base for the G&H side mount, I was able to put the screw holes for the Echo mount to good use, with the addition of the two obligatory hardened taper pins G&H provides. Thirty-five years later the rig still holds up well.