Steve,
Your photo is so far back it's hard to tell, but here's mine. Maybe not original, but possibly is because so little on my car was changed except the air cleaner, mufflers and a few other small bits. Hope it helps, but I don't see any markings on it.
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.