I just use a 12" bench plane. It will do the job quickly if you have a good vice setup. If I wanted the overlay to be 1" long, I would do a couple of strokes starting 1/4" from the tip, on the bow's back going towards the tip, then a couple more starting at 1/2", then 3/4, then finish off with one or two 1" strokes. That gives the angle to the joint. I would have the depth of cut set for very thin shavings. If you made any mistakes or got chattering, you could touch it up with a good flat sanding block. The easiest mistake is to roll the plane or sanding block side to side as you move it along the bow, and you end up with a convex surface instead of flat surface, or the surface is flat but angled to the side.