ZN-40 case/N64 trigger buttons question.

[Carp]

So I'm going to get the ZN-40 case most likely, and I want to be able to get trigger buttons on the back, most likely from a ps1 controller which would be two z buttons and the left and right bumpers. So I would need an area that is wide enough to hold those buttons on the back, but I don't think the plastic is wide enough, is their any way I could make it wider because I have seen other people with the same case who have made it wider.

I want it to look like this.







Case - http://www.polycase.com/zn-40

 

[Crazy Inventor]

i'm not he best when it comes to cases, but I did try something like this. I added extra plastic where I wanted it, cut what was between the case and what I just added so it was a hole. And then sanded, added bondo, sanded again, until it was smooth(ish). that's what I did. But again, I'm not great with cases, so seek others' advice.