That was my mom's second washer. I saw a couple of these in Coppertone on ebay a few years back. As compared to other machines of the mid-70s, I have not seen very many of these. They were available as Appnut said in '74 and '75 and were some of the models that made for the quick transition to large capacity machines during the mid 70s.
This is a 60-series set 1974 set, and there was an 80-series for '74 was well, followed by a 50 and 70 series in '75. There was also four 24-inch models and at least one standard capacity 29-inch machine, all which shared one variant or another of this control panel.
Very cool machines!
Gordon