The reason for the heat is to flatten it out. Usually it will get heated till flat and then clamped to stay that way. It's still gonna curl on you. if you are talking knife handles I would HIGHLY recommend using Loveless Bolts or Corby bolts as your fasteners instead of just pins. Buffalo horn wants to go back to its original curved shape over time. Polishing is very simple. Handsand to about 600 grit and then buff. Start your buffing with a fast cut then hit with a medium and then pink scratchless or white compound for a final finish. One secret is to have plenty of compound on your wheel or the horn will burn. If you forget and burn a small area ya can go back over it with plenty of compound and fix it.
I was rehandling this bolo for a friend. We used buffalo horn as that's what was on it originally when he bought it in the Philippines many years ago when he was stationed there as a Marine.
I used Loveless bolts for the fasteners. And buffed:
Building a sheath for it right now.