1961 was the last year of Desoto.

The inner fender wells are not structural. But they mount the battery box, starter relay, and voltage regulator on the left fender well. The wire harness has wires that go to ground at the voltage regulator bolt.

The rear bumper shape is the same on 1960 Chrysler but they had different or deleted bumper guards, not that big bumper guard in the center like that desoto picture. I have a 69 Chrysler I can measure or take photos of the brackets underneath to see if it will fit your car.