Attention when adapting to your own keyboard:

• Measure the front and back rims, but if your keyboard has this button part, make sure to account for that.
• Print a test piece for the fit! This can be something like 20mm. The print for a large keyboard goes to something like 350gr total, so don't waste filament on a bad fit ;) You can easily do this by opening the model in your slicer and making 2 cuts, in order to have a little band of the middle. 
• When printing the first part, ensure it goes to (at least) the middle. I added quite some offset, but you never know with other printers
  
  Shout out to Krakert for the excellent model.