True... PPG Acrylic Enamel was OEM. How about a single stage urethane? very durable finish with just enough peel in it. Or you could color sand it for a glass like shine, but then it wouldnt be like OEM. oh well..your choice.Base clear is most common for restos depending on the final results you are looking for. If your Duster still has a original spot of factory color on it, have your painter do a drop down panel for closest match.
Good luck and hope to see pics soon.
HR 20