How Rare? Asking for additional information

Regional Zone Offices would 'swap' 1973 Duster 340's with other Zones, to
fill a need.

As well as Dealer's who {swapped} needed a 'particular color' or desired option on a
Dealer Stocking Lot car.

This is not to say, that several 'Mist Green' Duster 340's didn't end up all
over the country, as there was about 3000 Plymouth Dealership's in 1973
that sold nearly 1,000,000 cars in total.