cutout

Hi, while I'm collecting my thoughts on what my next case will be I wanted to mod/have some fun with my current Ncase M1 ... particularly with the snap on side panels. I was wondering if any of you guys have done such atrocity as to have your side panels modified? I'm talking about filling up...

I've been working on a case for personal project of mine for a while and I'm about to get the parts cut soon, but I'm not sure about the dimensions for the rear I/O cutouts. Results from google and grabcad vary and I am afraid to get it wrong. I have been using mainly this image as reference...