If I am reading this right it would take four cuts, I use a hack saw. The center two being space how ever wide you want your strap the outer two
however wide you want your rings to be, Then taper back from the tip and the butt to the out side two cuts. I use rasps,files,scrapers, sand paper and steel wool, mostly in that order, If you take a 1/4 to 3/8 rasp and make the two outside edges safe you can use it to cut between your two center lines. Start it out at about a 45 degree angle. Then use it to start the taper on the out side cuts.
I hope this is helpful. Some things are easier done than said or written.
Tim C.