I took the original STL files from @Mohvee and I modified:
Here is the TinkerCad source if you want to update anything I've done.
https://www.tinkercad.com/things/iMNRLu9LUzb-9mm-case-slider
9mm_case_slider_Left_w_key.stl | 66.3KB | |
9mm_case_slider_Right_w_key.stl | 52.7KB |