A pico projector mounted in the neck area of the shell could possibly be used to rear-project a decent image, if the screen area could be made opaque. I just tried an experiment with my pico pocket projector (PK101) and it will focus close enough, but the image at that distance is only about 5 x 7 inches. An additional lens structure could perhaps be employed to provide an image large enough to cover the screen.
You will not find a color CRT that will fit the shell... sorry.
jr