Modeled up this bad boy. They're like 10 bucks on amazon, or 20 at MicroCenter. Got as close as I could with calipers and OnShape. Accuracy is probably +/- 0.1 if I had to guess, definitely more than good enough for modeling anything 3D-printing related (FDM at least). Trying to see how reliable I can make these things in the best-case scenario, so I've modeled up a "strengthener" for the device so it doesn't sag and bend the USB connector under the weight of a long or heavy HDMI cable. That will be posted soon!