Mike, I disagree with your time frame assessment. The small square flat button models were the lowest model rotoracks. The elongated buttons as seen on this model were for the higher end models. And were that way until Sears did away with the rotorack design with their revamped dishwasher line with the typical upper rack in like 1975 or 1976. We got a next to LK rotorack model for our house in Houston sometime in 1972 before the end of my sr. year in high school (May 1973). It didn't have the heated/cool dry rocker switch the above shown unit has. That feature was only on the last of the rotorack model line. A friend from college, his parents updated their early 1961/1962 GE Kitchen (with the first wash am GE) with a Kenmore kitchen features an induction cooktop and also a Kenmore dishwasher, the very first non rotorack Kenmore I'd ever seen. And it had the small square flat buttons, along with redesigned control knob. And that was sometime around 1975-1977. A woman from church I used to work with on musician stuff, I went to her house while I was still in high school. I noticed she had a Kenmore dishwasher and it had the small flat square buttons on the control panel. I recognized it as a low-end model. I about fell out on the floor when she opened the door to put some glasses in it and low and behold it was a roto rack. And this was whiie I was still in high school.