This is such a cute idea. If only I had been that clever in high school (and if only my dinosaur TI came with such things like colored faceplates).
You aren't that old--Mine is a TI-81 !! It's eleven years old, from when I took AP Calc in high school, and I have to say that I am STILL proud of it and it's one of my favorite possessions. As a college English instructor, I have no need to graph a damn thing, but I still use that guy for basic adding and subtracting.