It turns out that the card I was using failed. I had another similar to it, and it is working. In fact, I am posting from the machine I've been trying to get to function.

It had initially worked and both monitors were recognized. Then I thought I had done something that caused a problem with the configuration. Turns out, not the case.

It is hard (at least for me) to tell when the card itself is bad, or when something is configured wrong for using that card. I have tried to diagnose a software problem more than once before it became obvious (to me) that this was either a firmware or hardware failure outside of the "control" of the O/S or driver code.

I now have this system running SLED 12 SP4 configured the way the old system ran with the two monitors using SP3.

OH, what I did was do an Install of SLED 12 SP4 and not an upgrade. Seems that the UEFI stuff didn't upgrade so nicely. But with an INSTALL: the right video driver appears to be running and the monitors are "configurable" just as they had been on the original system, the raid /home is working such that all the applications that the user had been running are working as if nothing had ever failed (what backups are for, you take them you don't need them -- don't take them and you wish you had).

So this should be the end of this thread.