The switch works perfectly!
Because the large Flair elements draw 2.65kW, it's important to have an indirect infinite control which works in that range. This brand new one does - it was made in late 2016, by the way - and it controls the element very well.
Perfect slot in, even the connections are in the exact same place as the originals from Proctor-Silex.
Not the best controls, ever, but let's hope, having made it 50+ years, they have a few more ahead of them.
And, of course, due to the generosity of a member, our '78 Maytag Center Dial is up and running perfectly. I am no fan of timer 'issues' and was very, very happy to receive the help!
So, now we have to decide what to do with the '60/'61. This now working Flair was to have been the 'parts-donor' but turned out to be in nearly perfect condition. On the one hand, it would be awful to throw away several hundred hours of work (my husband's, not mine) on it. On the other hand, looking at Ebay prices for trim and other parts.....