$3500 doesn't surprise me. I've seen many much more common porcelain Ford oval signs go for near that much and this is a pretty rare sign. We had a Waterloo Thrasher tractor sign that was beat up pretty bad and it went nearly half of that. I would think the following for Detomaso would be stronger than Waterloo tractors. Signs and old gas pumps seem to be bringing decent money right now.
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.