No fiberglass company that I know of, makes an older roadster body that is specifically a Dodge or Plymouth............but then they don't come close to looking like a factory body anyway, so what does it matter. Call it whatever you want it to be.
Guess you could buy one of McCoys Duster bodies, hack the roof and build a Duster roadster. You didn't specify how nostalgic you wanted.
I think Suncoast race cars in Florida used to make one, I thought I saw them advertised somewhere years ago but can't be sure of even if the are still in business. Might be worth some research though.
I built my brother a nostalgic altered that he wanted.. was a 23 body... pretty simple little ride... he looked around for different bodies back then and they were FEW and far between... this was about 20 years ago
Suncoast makes a "30 series" roadster body and you can get it with different grille shells, to make it a 33 Ford, Mopar or Chevy, but it's all the same body and fenders. They also make a 37 roadster in all makes, which again is the same rear section, with different noses. They make a Viper roadster as well
I've had mine a few years now and love it. Mine is spitzer body; 33 Dodge or Plymouth. I've parked it beside a legit 33 at the Mopar nats and they are very close. Mine is fairly consistent and has gone a few rounds. I run pro usually and oƧcasionally s/pro running 6.0's or 9.70's with a little 383 mopar.
Older ones weren't built for the high horsepower some folks try to throw at them. They are deadly 5.50 and slower in the 1/8th.
Left steer roadster chassis cert changed a ton in the early 2000's so if the car has an expired cert it may need bars to recert. Bob's ProFab added like 10 bars to my car. Also an antiroll,front brakes, 4 link and front suspension would be preferred.