Hey everyone just wanted to come back and say I tried a combination of methods, essentially just tempering the spine of the blade while it was the clamped and shimmed, followed by immediately dunking in water.
Happy to say it worked perfectly!!!
Here are some pics showing the process with a short description.
The key is to protect the cutting edge with some wet paper towel, so that the heat doesn't travel too far down.
Take two pieces of straight aluminum or steel, then place a folded piece of wet paper towel for the cutting edge to lie on.
Similar to straightening using oven tempering, it worked best by clamping the blade so that after shimming it is now curving in the opposite direction with the same amount of counter-curve.
Using washers or anything thin and flat to shim the blade, place the shims in the proper area to get the right counter-curve when sandwiched/pressed between the two outer pieces of metal.
Clamp so that it holds together but make sure to not clamp down too much at risk of cracking your blade.
Using a gas torch, pass the flame back and forth along the spine of the knife until it takes on a deeper yellow-brown color. I believe it just needs to be higher than original temper, for mine the initial temper was a light straw color so I took mine to dark yellow-brown along the spine (mine was less even than I would have liked it to be but still worked).
Once you've tempered the spine to the right color, and while still hot, dunk in water.
Take it apart and check, all the while keeping those fingers crossed!
Last pic is the knife on top of my new anvil which is perfectly flat.
(I didn't want to also hold my iPad and photograph while actually heating with the torch so in this photo it's just staged
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