Sure you can, I drilled two holes in the back of my 4912. There are no lines running thru the plastic bump in the back. I used a picture from BierMuncher's gallery as a guide.
I want to be able to keep my regualtor and CO2 outside the fridge so that I can have better control over the pressure indicators. Im growing tired of adjusting the pressure and having to wait 4 hours for the actual adjustment to take place on the gauge. Thanks again!!