Truck Forums - Speedometer casing? Help!

haha i need your guys help. Me and my buddies were messing around in my dads truck and got bug spray on the glass/plastic that covers the speedometer and stuff and its chemicals burned into the plastic. And of course dad is pretty pissed at me and the truck is his baby so i really need to find a replacement piece for that. ive looked all over with no luck so i need some profesional help. So do you guys have any websites or anything that i can find something like this? Its a 1996 gmc truck. I wanna fix this for him but i need some help. Please Help!!! Thanks Guys!!!