Dennis, try the lazy solution. If it leaks at a corner, wipe and brush that corner with gasoline from beneath (wear goggles). Let dry. Apply plenty of RTV. Let dry 24 hours.
I know this is a stop gap solution, sometimes it works, sometimes it doesn't. I did it once with success, knowing that the engine would have to come out next year anyway, and it worked. Worth trying?
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.