My advice is unless you no longer have the car, don't sell them. They will increase the value of an all original car by at least what you could sell them for, AND make the car much easier to sell. And if you still have the car, maybe in a few years you'll regret selling them? That said, I think that you could expect around $7.5K properly marketed and if they are undamaged.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.