Maybe it could be possible but the keyboard would need to be really big but i don't think so, and if you're goin to use laptop hardware you would have to sacrifice the whole laptop for your proyect, it COULD work. Why you just don't make a PC with Apple style? A monitor with all the PC hardware inside? Sounds crazy but i think it can work, less risky and more easy. Like you put the mobo on the top of the crt and HDD drive on bottom?
And the only problem with this freaky idea is the power supply, there wouldn't be space for it and the CRT must be 19 or 21+ of size