I wish I could help you, but from a Kenmores and Whirlpool perspective, I can't offer much that won't further confuse the subject, especially with KM.
In a nutshell, these have debuted at many times, and their year models seem to indicate when they were designed, NOT necessarily the year for which they were introduced. Not only that, but many models have lasted in production for a number of years, while others for only a year or less.
Here's what helps me draw those conclusions (or lack thereof):
Probably the best example of model-year machines that I can point a finger at involves the complete and near total re-design of the 1976 Kenmore wet-face, "black panel" machines. This was a total re-vamp of almost the full line of machines, even the plastic top BOL machines got new models. The first of these were on the store sales floors in the fall of 1975. Some of the 1975s continued for a while, especially in catalog sales, but the complete new '76 line was out in force in the fall/winter of 1975. I had a 76 60-series machine early in my rebuilding days that was made in the 40th week or so of 1975. This would be just like typical automotive model years.
That said, many of the '76 models were done and replaced by '77s. There was a change in 1977 that Sears did as an advertising gimick to separate the Knit-Delicate cycle into two, though this was nothing more than a graphics change on the console. Every model that was affected by this though got a new 1977 model number as each machine gained a 'cycle' in advertising (a 4-cycle machine suddenly became a 5-cycle). BUT, the handful of 1976 models that weren't affected lasted in production into 1978. One example was a '76 60-series large cap. machine that had Normal, Perm Press, and Short wash (no delicate). That model was available for several years with it's original model number. If one of us ever gets one of those that was manufactured in fall 1977 for example, what is it, a '76 or a '77 model?
I have a machine that falls into that category now...in fact I probably have more than one, but it's a 1979 model 80-series, but it was made in the spring of 1980 and is currently my daily driver. I just refer to it as the 79/80. No idea how else to refer to it. I have three others of this machine though, one made in late 1978, one in 1979, and one made in 1981 - all the same model number.
Some more illustrious models that had this sort of history are the 1963 Lady Ks, which were made into 1965 (yes, after two other Lady K models were developed), the 1965 Kenmore 800, which was made as late as 1968, and much of the entire 1983 belt-drive line, which was made into the early fall of 1986.
Adding another twist, another full-line introduction which superceeded all the previoius was the 1983 line, which replaced a variety of 1981 and 1982 models, but it wasn't widely available until the second half of 1983. Some models came earlier than others, but most came out in fall 1983 (as '83 models) while the most popular remmant 1981 and 1982 models were still in the catalogs and still involved in sales promotions on sales floors. It would seem really that these machines should have been numbered as 1984 models.
To wrap all this up, at least from what I find in Kenmore history, model numbers genarally tell for what year the model was devised, but that model's introduction could have come at any time during the year, and it could have remained in production for quite some time. In my mind I just keep the model year and the production year separate.
I hope I didn't further confuse you!
Gordon
