There is no logical, scientifically reasonable explanation as to why changing the new drive's letter to the old drive's letter should not have fooled digiKam into being none the wiser and went along as if nothing new had happened; alas........., after swapping around the drive letters, digiKam just swapped also and ignored the new drive, still remaining associated with the old drive and it's new drive letter.
So, to prevent further confusion in other programs that had already aligned themselves with the new drive, I changed the letters back to their previous state.
I do have digiKam set to always write metadata such that it remains with the jpeg file no matter where it may go from here.
I counted my collections and there are currently thirty-five of them, so I printed a screen-shot of the collections list and have been one-by-one deleting and then reinstating the collections a few at a time.
I have numerous image handling programs and in every case except for digiKam it is a simple matter to realign the program with a new drive.
Actually, I was very surprised to find that changing the drive letters did not work.
Thanks so much for helping.