I read great reviews about a product called Eastwood Plastic Resurfacer for restoring plastic automotive parts. So, I gave it a shot on the 750 GT's dashboard and it exceeded my expectations!

Results after a few coats of the Plastic Resurfacer.

Before restoration.

After restoration and applying white model paint with a very fine brush. I don't think white markings look much better than pre-restoration, but that's probably as good as it looked from the factory.