"Does anyone have a pic of an early 70's Corning brand smooth-top? "
There was a Corning smooth electric cooktop in this home when I bought it. It was white, with aluminum (or maybe stainless) control knobs and lots to starburst patterns on the glass. I removed it and converted the cooktop over to a modern black Frigidaire Gallery "Gas on Glass" cooktop (hint: there are better choices).
I was intending to keep the Corning cooktop around as a curiosity, but made the mistake of leaning it against the outside of a garage door, and then forgetting it was there when I opened the door from the inside. Glass doesn't like being slammed into concrete ;-(. Never did get a pic, but it really wasn't anything all that amazing, IMHO. The cooktop did have a nasty habit, of not fully turning off on some of the burners. Probably a relatively simple control feature, but still it didn't endear itself to me in addition to not being gas.