Emissions Control System ID help, 1971 Duster 340

ECS found in CA emissions cars in 1970, on all A-bodies in 1971. Under the tube attached to the fenderwell (under the car) there should be a sheetmetal cover (easy to remove). It should cover the 4 lines going to the tank and with the cover removed you can verify it is a ECS tank. That tank has a tank within a tank (maybe a gallon?) that has a rubber drain plug on the top of the tank. Photos of an ECS tank out of the car to follow.