O.K. so this isn't an M-body chrysler, it's a 1976 Plymouth Volare that was owned by my Grandfather. The m-bodies were based on this car and had similar drive trains, chassis, and sizes.
This 1979 Plymouth Caravelle is the Canadian version of the Dodge Diplomat. During the 80's the Caravelle was a Plymouth version of the Dodge 600 but in Canada we had a M-body one at the same time know as the Caravelle Salon. The salon was the Canadian version of the Gran Fury.
This is a Plymouth Gran Fury. They were also an m-body.
Gran Fury/Diplomat/New Yorker Page
A 78 Plymouth Caravelle Coupe.
This red 1978 Caravelle coupe appeared on the front of the sales brochure for that year.