Thanks for all your inputs. Here is my next step:

As a proof of concept, I 3D printed a stick 0.05” thick, 1” wide, and 6” long. It is white with black text. Total print time 30 minutes.

One edge has a series of cut outs. Between each cutout is a 0.1” wide finger. The first cut out is 5/64” wide. I increment by 1/64” up to 3/8”. All odd 64ths are labeled (5, 7, 9, etc).

I can lay a cut out on top of the SHCS and easily see the closest size. Time will tell if this tool is useful.