You can make that "thing" out of sheet metal and just cover it with the vinyl fabric. I have one but it's on my original dash, spare dash and to get it you have to buy the entire car...I mean dash.
Just make the thing. That's the simplest solution. Maybe some one like Hall still has it separately or maybe Wilkinson. They were both purchasers of original Pantera parts when they were new and lots of obscure parts like this are still in the bin.
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.