JCochrane,
Thank you for posting! This presentation-grade rifle is now clearly in the hands of someone who appreciates it. I'm also glad you plan to shoot it... Guns are made to be shot.
This rifle has so many outstanding features, it's hard to take them all in. The "Killdeer/Deerslayer" name, rendered in Cherokee, is particularly intriguing, considering your interest in The Last of the Mohicans. Many native people believed that everything that exists is alive, and that even seemingly inanimate objects have "agency," the ability to make things happen. Maybe that rifle called you over, and put itself in your hands.
The carving, engraving, and silver wire inlay are all outstanding. However, that wire inlay on the cheekpiece really caught my eye. The design is reminiscent of the "double curve motif" frequently seen in native Woodland art. The design itself is significant, and when the pattern was made to be symmetric, like this one, it is generally believed to symbolize balance or harmony.
One final thought... The tag on the gun said .52 caliber. I think you were right to question that. However, it can be very difficult to get an accurate measure of the bore with calipers. If the jaws of the device are not exactly opposite each other across the exact center of the bore, or if they are even slightly canted in any direction, you will get an undersized measure. Another thing is the jaws of the caliper have a very slight flat, while the inside of the bore is radiused, so the edges of the caliper jaws will contact the bore, while the "wall" will arc above the center of the jaw. This will also contribute to an undersized measure, even if the caliper is correctly positioned and not canted. Hard to describe, but definitely something to consider. If it were me, I would try to get ahold of a variety of balls in the general range of sizes you might expect to use and I would try them out to see how they load and shoot before investing in a mould. You can always melt and recast the undersized and oversized balls after you have obtained a mould for balls of the correct diameter.
In any event, I want to congratulate you for finding this superb rifle. I don't think it could be in better hands.
Notchy Bob