Lately I have seen listed on ebay a replacement dash for early X's from Ricambi - Automobilia, Netherlands. It's fiberglass; can not tell if it is a cap over the old or a total replacement. Price listed is about $330 plus shipping.
I first restored my origoinal dash using a pliable bondo to fill in the cracks, covered the weak areas with a very light weight fiberglass cloth, filler coat, lots of sanding then used a truck bed coating to paint with, gives a texture, clovers up a lot of flaws and is very durable. I ended replacing the old dash with a late model dash that has a better/efficent design.
rbk