Alright, this Duchess has Chevrolet Chevette mechanicals.
Yes. As far as I can make out, the Duchess was originally designed in the UK to be built on Herald/Vitesse bases, but the idea was franchised to the US, where several were built on a variety of donor cars.
The puzzle car was found on a thread where the author says it was used by his father as a "loaner" from a garage!