Gordon:
"Sandy - The 1965 Kenmore BOL, if it was a 29-inch machine, was most likely a 400 series, is that right?"
It was a 29-inch machine, but I could not for the life of me tell you what the model number was. I was embarrassed by the machines, for all that they were a brand-new matched set, because at that time Mom was still in her "BOL's all you need" mode (she would later become the Queen of TOL, not that she took care of TOL stuff any better than she had BOL stuff). Everyone else we knew had much fancier machines; my paternal grandmother had a new set of Kenmore 800's, and her next-door neighbor had a set of keyboard Lady K's. My second cousin's wife had a 1962 or '63 set of turquoise Lady K's (gorgeous, but unreliable as hell), and my mom's sister had GE's that weren't fancy, but still nicer than our set.
Mom used them for nine years, until they moved from the house I grew up in, and then sold them on. I do not recall any breakdowns, which given Mom's "work it 'til it drops" philosophy, was pretty good.