The options here are dash mat ($40), dash overlay ($150), refurbish ($400), new replacement ($1400 if you can find one), or something altogether different. You can guess what I'm going with...I got this idea from a guy online who fixed up his MG dash. The idea is to fill all the cracks with silicone, then glue a new piece of vinyl fabric over the top. First step is to clean it up and flatten it out. The edges of all the cracks are curled up, so simply filling them in wouldn't make a flat surface. I sliced off the curled edges and dug out all the loose foam.
Now I'm ready to fill the cracks. I got some black silicone, worked it into the cracks, and smoothed it over with a putty knife. So far so good!
The next step will be to trim and glue the vinyl fabric on, but I have to wait for it to dry for a while so more on that later.
On another note, my adapter plate is nearly done! I should be ready to fill this void with the electric motor soon.
Here's the nearly finished adapter plate.