The new keyboard, which I ordered Friday afternoon, was supposed to arrive on or before next Wednesday, but was found in the mailbox yesterday (Sunday) afternoon; I'd fairly sure it wasn't there in the morning!
I just did the part exchange, which took a bit longer than I expected. The new ribbon wasn't as stiff, probably being thinner material, and I had some difficulty getting it to go into the connector. I cut a 1" wide strip of plastic from a milk container to experiment with...originally it actually being 1.010 wide, and I had the same problem, finally getting it to go in after reducing the width to .980". The old ribbon was closer to that, while the new was nearer to a full 1.000", and I considered trimming it but decided against that idea. More persistent effort at pushing it in while trying to keep it bowed a bit finally succeeded in seating it squarely at the correct depth. I was surprised by the trouble occurring.
Anyway, I am now typing normally again, using all keys.
Now comes trying to troubleshoot the old one, if only for education. That will have to wait a while though, so I probably should mark this thread as "Solved" now.
Thanks for the help and encouragement.
Edited by TooNew2, 18 September 2017 - 09:34 AM.