Nice one!
I once considered a similar project to a dying Classic, placing a miniITX or laptop board in it, but trying to find a 9" LCD screen* as I didn't have the confidence to poke about with the original CRT.
*( There is a bar in the university area I used to frequent which has old TVs but with LCD screens in. It works well, albeit the curved edges aren't as big a deal on a TV picture than a PC picture. Could get a monitor which had a border at smaller resolutions, a bit like some laptop screens do)
In fact, something like an Acer Aspire One has a 9" screen and a small factor intel atom board. And I have hackintoshed mine. Might be an interesting project....
Ended up selling the dying classic to a local collector, but later found a working classic 2 to replace it (and this one is definitely NOT getting gutted!).