If you are going to paint the dash do you want a real metal dash or would a wood dash painted to look like you want be ok. You could use your original dash to copy it using MDF ( medium density fiberboard) This board is very flat and is easy to paint and seal. Another possibility is to have it wrapped like cars are wrapped now days instead of being painted. I am sure you could find a wrinkle finish or hammered finish that would nice. Frank