Mark did you try to test the loop with a megger once removed? I remember it being a way to find intermittent loop failures but blurb in the manual that the loop must be clean prior to using the megger.
Actually after looking back in my files I had already started a new one in CAD it has dimensions as well, its slightly bigger than the one i posted above I wanted to slightly increase the size because depending on how the pins were put in they could kind of get stuck. I never finished cleaning it up but attached is another STL and Autodesk file with dimensions.
I think I see your issue, when I open the file in blender and Creality the model is sharp, I opened it in meshmixer and I see the odd lines and fragmented faces. I think it just comes down to the boolean operations destroying the faces. Let me know if your not able to get it to turn out I will re create it in Autodesk tomorrow.