I would let it be. It was arsenal updated and is in the configuration it wore, when it left the U.S. service.

(This is not rehabbing Bubba's Deer Rifle into a palatable presence).

It is a neat story that it also served, in an earlier guise, at a documented historical event.

I see no point in changing a legitimate U.S. Arm. A knowledgeable collector will appreciate the whole story and treasure it, as it is.

Also, who knows what obscure list or record of Krag serial numbers could show up in the future?

p.s. You should sell the other model 1896 carbine to me!