sun visor(s) & main light switch plug

I'm doing some experimenting with stuff and am planning to replace the fog light switch with a main light switch and diode giving me off/rear/front&rear for the fogs plus I'm also looking at cutting the visors down along the line where there is a step, scooping it out a bit and fitting an LCD screen and keyboard into it which will interface with my mobile which can be sat in a bracket. I can then follow my sat nag without taking my eyes off the road and use the screen for other stuff too. I don't want to ruin the existing setup by cutting the fog light switch off or ruining the visor so was wandering if anyone has a couple of bits of old scratp that they don't want. The visor can be battered and any colour.....

Cheers.