The problem is solved! - and boy do I feel stupid. It was "pilot error" all the time.Thank you all for your help, and for spending some time and sharing your knowledge with me. I've actually learned a lot here, even though none of it fixed the problem. You are all great friends and your efforts are appreciated.
So here we go.
A long time ago, I was using an app that amplified my typing noises via the internal mic through the external amplified speakers. It was so long ago, that I don't even remember which program it was that did that.
ThinkPad has a function key to turn off the internal mic. Fn+F4. When it does, a little orange LED lights up. The computer remembers this setting until I press Fn+F4 again.

As you can see, this is a microphone icon, and it did the job of turning the internal mic off.
Great ideas come in the 3 B's - the bed, the bath, and the bus. This one came in the bed. I only got about 4 hours of sleep last night so I took a little 45 minute "power nap" after lunch. I woke and wondered if this turned off just the mic or all the audio.
The icon looks like a microphone, so I had no reason to suspect that it would turn anything but the mic off, but I've been grasping for straws for days before I even posted the first message here. So I tried it.
IT WORKS!!! Even my old UA-1A interfaces work with the generic Windows drivers!!!!!!!!! The elation of finally fixing the problem has more than overwhelmed the embarrassment of feeling so stupid that I didn't try that first.
Now I'll try installing the 32 bit M-Track drivers and see if it works with my new toy.
Thanks again for your help!
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