Note that if you want a nice and narrow bevel, you'll have to do some grinding post HT as well. And as Charlie said, don't go above 4:1 (or below 1:4 ) because you'll just make your life more difficult than it needs to be. Also, how thick is the tail? I ask because it looks fairly thick though I can't really tell how thick.. Remember that the tail has to be able to swivel between the scales.

Btw, you mention that the width should be to just below the notch for the proper ratio. If you do that, you can make the blade just a tad shorter and create a new notch closer to the spine if you have reservations about the current location of the notch.