IMO:
The second photo seems to indicate an uneven tapered tang, much thicker at the front, then at the rear.
And thinner yet in the middle.
That would take some doing to exactly fit Micarta scales to the tang.
Unless you were willing to settle for less then perfect fit, and be happy with epoxy bedding that would be secure, but somewhat unsightly.
If the horn scales are loose?
Put some CA adhesive in the joints. (Hot Stuff, Crazy Glue, etc.)
If the scales are too smooth?
Wrap them with friction tape, ball bat tape, etc.
I think if I were to re-handle it seamlessly on that goofy tang with canvas Micarta?
I would have to charge more then the knife is worth to do it!
rc