Like the title says, do they exist? What years will interchange?
83 and 84s were the same. I don't think anyone makes original pads anymore, but they do make overlays.
http://www.coolcats.net/modifying/dashtop.html
Overlays can be covered in vinyl or leather to disguise the plastic look and feel. I have one up for grabs that has never been used.
I also had an idea to fill the existing cracks with some expandable foam and then recover the original pad in vinyl. I went in a different direction though and made a whole dash pad out of scratch that was deeply hooded. I scratched the use of that when realized the entire plastic dash shell was cracking in too many places and needed an entire dash replacement. I had no luck finding 83-84 dashes so I decided to go with a 95 Mustang dash swap for a unique look. However, a 85-88 dash swap is much easier because there is nothing to fabricate or modify. It bolts right in.