Congratulations!

I'm very happy for you.
Definitely take the advice to *frist run this rifle as .458 Winchester* -- and then re-visit your interest in rechambering the rifle.

Here in the 21st Century, the .458 Winchester is everything it was planned to be, with perfectly effective bullets and very effective and consistent powders and primers.
It'll do it all.

Take a look at our fellow member, JPK

He's taken numerous elephant with his .458 Winchester SxS Double Rifle.
Go through his posts and see the path he took with his .458 rifle, and where he stands currently on the cartridge.

I won't attempt to stand between you and your plans to refinish the wood -- and I will applaud you on your statement of interest in ditching the white line spacer too!

I look forward to seeing how you progress with the rifle, at the workbench, at the target, and in the field!

--Tinker