Been meaning to post this one up for a few weeks now.
Attached is the STL file for my C9 design
I have printed these successfully in Natural ABS with the following basic slicing parameters
Layer Height: 0.2mm
Layer Width: 0.44mm
Nozzle: 0.4mm
Speed: variable in S3D, base and top needs to be down to maybe 30mm/sec
These are sized a little tight on the base hole to allow for some pixels I have that are closer to 11mm than 12mm hole requirement.
You could scale the model fractionally if you need to.
These look like

STL file in Zip
Attached is the STL file for my C9 design
I have printed these successfully in Natural ABS with the following basic slicing parameters
Layer Height: 0.2mm
Layer Width: 0.44mm
Nozzle: 0.4mm
Speed: variable in S3D, base and top needs to be down to maybe 30mm/sec
These are sized a little tight on the base hole to allow for some pixels I have that are closer to 11mm than 12mm hole requirement.
You could scale the model fractionally if you need to.
These look like

STL file in Zip