Wedge dimension?

So I'm taking a crack at my first set of custom scales for a Boker "big Chief" with a piece of 1/8" thick walnut.
To play it safe on my maiden voyage,I simply traced the shape of the un-cracked side of the scales that came off.
Now I could try to reuse the old wedge (metal) but thought it might look nicer with a custom wedge.
Here's my dilemma,I'm not too sure what exactly the wedge shape is for or how to figure the correct angle,thickness,material.

Here is a complete tutorial by Charlie Lewis which includes measuring for the wedge at the end
https://www.youtube.com/watch?v=-6CM96fELd8

Read through the sticky at the top of the forum page. Welcome to the Workshop: How do I / Where do I / What do I / answers are here. Tons of information there.
Good luck,
Karl