You hit my funnybone.
I have an affinity for bone on my guns, and have placed inlyas in the wooden patchbox cover, at the tip of the patchbox cover, in the cheekpiece and in the wrist.
I have also used it at the muzzle, at the butt of the wood patchbox cover and as a toe plate. That's where it is at its weakest.
It'll stand out in a striking way against a dark finish. I learned several things the hard way;
You have to decide early whether you want more white or preservation of any yellow, and especially the nature and placement of the bone. It is easy to clash with the rest of the rifle.
Make sure you bevel the edges carefully and fully on your inlay. It won't fit, especially on a curve, if you don't.
A good set of needle files and nail files will be helpful for the bevel
Gently, boy, gently
If up end up with a little gap, a bit of crazy glue in the gap and some careful filing outward over the gap will throw the dust into the gap and cover your boo-boo. Let it dry and then sand and whisker.
You won't have to polish it if you are thorough in whiskering
Be real careful about tapping the bone into place...especially with your antique. You can't tell how brittle it is with the naked eye.
Since you can't judge how the stain will react with it, unless you are acid based or Aqua Fortis, coat it with rubber cement before staining the gun. Make sure it covers by looking at it in sunlight. When you rub off the cement the finish will be in tact.
I guess aqua fortis or similar requires that you take the inlays out before staining.
Please make sure you post some pics.
Don't shoot yore eye out, kid
The Capgun Kid