IBM Model M "M Star Classic" USB C adapter

This model holds a USB C breakout board in the port opening of an IBM model M, over top of a M Star Classic USB Conversion board, inside an IBM Model M keyboard. I used the included USB A connector, with a short cable to connect the USB C board to the USB A port, but you could also solder jumper wires directly from the USB C Breakout board to the conversion board. This requires no modification to the controller board, or to the keyboard housing. 

This model requires two M3x12mm screws, and two M3 heat inserts to hold the two halfs together. 

I printed these with a .4mm nozzle, .12mm layer height, 4 walls, supports on, and 25% infill.