I am pleased to hear my brain storming is on the right path with my "projected" lines. It's a lot more work than I anticipated, and with something that takes this much time I want to do it right instead of saying "good enough". I do agree with you on the belly of the handle, since with the index finger section revision, the belly will be a little pudgy.
With the initial bevel, is their any special technique to keep it even without over or under doing it? It would be a shame to get the whole thing cleaned up and the bevel being ruined.
Take a drill bit that is slightly thinner than your stock. Take some black paint and lightly spray coat the cutting edge. When its dry, lay the stock and drill on a flat surface and run the sharp part along the cutting edge. Flip the blade around and do it again. You should have two lines. Then, grind the cutting edge at about 45 degrees on both sides evenly until you hit the center lines. There should be a 0.5 to 1 mm "edge" between the two lines . This is your centerline before heat treating. If you go thinner the edge may become wiggly or wavy in HT. Spray paint a thin coat on both 45 degree sides and the blade itself.
Now get one of the small wrenches that clamp shut and don't open until you press the release lever. Place it where you want your ricasso to be and angle it in the angle your ricasso should be. Use the drill bit to mark your plunge line. You can also use a chainsaw file to file your ricasso before you grind, same technique as for the bevel grind below. file with less and less angle so your ricasso line creeps up to where you want it. Properly done you use a tool for this called a file guide instead of the wrench. Either keep the wrench in place when grinding but it can get in the way or free hand it but its easy to screw up the plunge cut line
Hold the knife in your left hand lightly only for positioning it. Hold it against the belt and use your finger (or a piece of thin wood along the cutting edge. Angle the blade and put pressure exactly on the point where the end of the 45 degree part goes into the blade. You should be holding the blade at around 7 to 10 degrees compared to the belt. Draw a black thin line across your belt. It should be parallel across the belt. Now, place your blade along that line and draw it out to your left. When you reach the curve on your blade keep the blade parallel to the drawn line. This mean you must twist the workpiece clockwise to keep it parallel. Ease up on the pushing pressure towards the pointy end. Practice this 20 times on both sides.
Get an old pan full of water to cool the blade when it gets too hot.
Turn on the belt and go for it. After every pass, check your blade. Where you placed it on the belt it will be silver. Vary the angle and pressure point to creep the silver up and down (mostly up at first) . At first it will be hard and quite tippy feeling. Then, as you get more flat it becomes stable and you can start varying the angle to get where you want.
When you get close, use very light pressure right in the middle of the flat until you get the grind to your marked grind lines at the cutting edge and wherever you marked the top unless its a full flat then there should be no mor spraypaint left over.
Send to heat treating. Repeat the above until its really thin, making sure to go slow and even and cool after every pass. Else you might damage the heat treat or only the tip making for a knife that sharpens and dulls very easy.
Its mostly practice its not that hard, go for it. If in doubt, just practice on a flat cheap bar of soft metal that your friend has laying around.
