Drilled saddle for CX: failed

Bad news: the project of drilling a saddle myself for my Superia Gemini Cross CX bike failed. Reason: you cannot simply drill leather with a drill for steel or plastic. No big deal: dream gone, saddle gone, Superia 'cross bike project will be continued with another, regular Arius Special Gran Carrera saddle.
I spent quite some time measuring, making and applying drilling templates, based on the original Assos and Arius drilled saddles. It all looked pretty good. But what seemed to be so simple ended in 30 minutes or so. Drilling small holes of 2 mm is easy, but going to the final diameter of 4 or 5 mm is a problem. You simply don't get nice, clean round holes in the leather. You either have to use a very special drill or, more likely, punch the holes with a special machine.
Right now I don't see a possibility to convert a regular saddle into a perforated saddle by myself, so I have to give up this idea for the time being.