Ok, I’m responding to my own post. I found the anwer. Yes, I should have researched before I ranted (usually do), but maybe this will help someone else with the problem of missing files. It’s very frustrating.
From a post on the “Basics” Forum:
In the project window, double-click on one of the pieces of missing footage. A window should open to navigate to the new location. Click on the footage in the new location, and AE should link to all the other missing footage in that folder.