1972 Duster Build with my Daughter

Remember this Duster is a '73 Dart from the Dash forward including the radiator/radiator support/AC condenser.

Ah, I see. Unfortunately, I couldn't find one online. Call these guys: Air Components & Manufacturing Inc | Automotive Air Conditioning Parts. Ask them is they can order that part. Make sure they know it is a UAC manufactured part so they can contact their appropriate supplier. They are likely your best chance. Another place to try is Arizona Mobile Air, Inc. | Automotive Air Conditioning Parts & Equipment. As a final resort, call UAC and see if you can buy it direct, or if they can point you to a distributor that can get it for you: Welcome to UAC.

Good luck!
Max