Possibly you can find some local Pantera folks that can take a look at the car. I am not an expert, but even if you are going to do a lot of the work yourself you can easily drop $25K + on this car. And as Cuvee mentioned you can usually double your costs with un expected repairs.
Good Luck and welcome.
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.