I got a Park Tool TS4.2 wheel truing stand from a shop that was closing a while back. With it being used, it didn't include the caliper caps. For a while, that wasn't a big deal, because all of my wheels were aluminum. However, I've started building a carbon gravel bike, and I want to be able to true the carbon rims without damaging them. Unfortunately, Park Tool only sells this part as a part of rebuild kits for their truing stands. Fortunately, I volunteer at a bike shop on the weekends, and I was able to get pictures and measurements of a caliper cap they had. A couple of hours in Fusion 360, and I have a rough model that fits onto the calipers.

The model itself could use some tweaks, such as rounding out the sides a bit more to make the contact point smaller. Remixes are welcomed and I may revise this in the future.

Credit to Pedal Station for letting me take pictures and measurements for reference.