I doubt it would hurt the value. It lessens the originality but originality isn't key to the value of the car in most cases. Only if you're looking to keep the entire car original for its investment value would this be an issue. Having a Windsor I'm sure would be preferred by some buyers as it allows for more flexibility in modifications e.g. increasing displacement.
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.