I like that set too James.
That is a 1981 or 1982 washer (I suspect 1982) and the dryer is an early 1983 model, perhaps late 1982 build date.
These are somewhat unusual models. The washer is a 70-series, but it is impossible to tell if its an 81 or 82 without looking at the model tag, or under the lid. The 81 had a manual filter - the only DA equipped machine ever to have a manual filter along with the DA (along with its pre-wash capable sibling) and the '82 has the self-cleaning filter. I think consumers rejected the '81 model with the manual filter in droves, and the '82 quickly arrived. In this period, Sears considered the three position water level something for the lower models, 500 series and down. Four levels in these big tubs was/is nice, but they are not very common today.
The dryer is an odd duck. It was usually higher-end 70-series models, at the least, which got a full-width door, but this is a single temp (no low heat) entry 70. In the '81 version, this model had no wrinkle guard and had the typical plug door, in fact it was the first Fabric Master model available. The next versions, the '83s, saw all the 70-series have the full width door, and wrinkle guard was added too for good measure. So its a nicely featured machine, but with just one heat setting. Shortly after this model was introduced, the easy-loader door debuted which has the wide oval opening, which makes loading and unloading a snap.
The next major model line was the '85 dryers --- Sears kept re-introducing dryer lines in the early 80s, altough they did not re-design the washer line after 1983. The '85 version of this dryer, which looked identical to the easy loader version of the '83, is what I wanted when I bought my machines new. The Sears salesman wouldn't have me buying a single heat dryer...so I ended up with the step-up model.
If this set has been together since new, I'd say they are late 1982 production or very early 1983.
Gordon