I’m not sure “I” worked it out, maybe X did with some nudging..
I quit the project on computer& Raid #2 and opened original project on Raid #1. That project appeared as expected with both original and proxy media linked up .
THen back to Raid #2 with the copied library and external media folder. With that Library open I grab one clip in the Browser and relink link the clip to the original media folder and the relink works. I grab 6 more clips and relink to original media and that works. So I grab the rest of the clips, numbering about 180 and relink with success.
Switched to proxy view and basically did the same thing with success. And so now the Library on Raid 2 with the external media works as expected.
I’m not sure the actions I took made any sense in terms of solving the problem, but maybe it gave X a nudge in the right direction and it healed itself.