Actually, this is not really an "early" DA....The Dual-Action agitator in these machines was about as refined as it got for a Belt-Drive.
The first DA models from late 1975 into 1977 had a spring loaded auger, which when coupled with an air pocket underneath, made the auger float above the center agitator where notches in the agitator engaged notches in the auger to drive it. This turned out to be a very noisy design, like playing cards in bicycle spokes, and it was revised internally in 1977 or so to have the side-facing agitator dogs that remained unchanged from then through 1986. This design is much quieter, and not as dependent on this air pocket, which doesn't form if the agiator's cap is loose.
The agitator wasn't changed again functionally until adapted for the Direct Drive, except for an underneath adaptation for small agitator fins to feed the basket mounted disk filter. These are not visible to the user. For the DDs, the number of dogs was doubled to cope with the increased number of engagements needed due to the short agitation strokes.
The gold set in this ad I'm guessing dates from 1980 models. I need to check the schematics, but either the 1980 or the 1981 model does not have the triple dispenser, and I am not sure which off-hand (check the pic in the ad, I don't see the dispenser lid). The dryer has the full-width door, which pre-dates the early 1983 EZ-Loader door.
The next major version of these was the 1982 Limited Edition, which is functionally similar but has different console trim.
Gordon