Anything is possible, just depends how hard it is to map the video signals and find a suitable replacement LCD, and interface the two.
For the PB100 I'm using an FPGA dev board to receive the 11 video signals for 640x400 and pixel-double them to 1280x800, then output to an LVDS encoder
My first thought was well for a PB100 you could probably just do the whole thing in a chunky-ish FPGA these days ;-)
E-ink sounds fun, I'd love an e-ink System 7 notebook.