Some further evidence in support of the sizing of our IDIC.
This photo is from Robert Withrow, who owns Kirk’s original dress uniform. He reports the average width of the original braiding to be 1". (Thank you so much to Robert for doing this research for us!)
And here is my CAD model overlaid with the screen cap from the show. Note that the blue line is 25.4mm wide, which is the same as 1"
Here is our Roddenberry.com IDIC on a dress uniform replica made for me by Ginger Holly of STC. The newer replica braiding available is a bit thinner than the original. I believe that they intentionally spread out the original braids a bit to a full 1" width before tacking them down onto the uniforms used in TOS.