The IP address of the neighbor is not enough? Can you identify the down tunnel from the hub router message?
You can filter on the message text using the neighbor IP address in a series of rules but 60+ rules would be a mess. I would create a script that has a case statement( you could also use if-else statements) that would match the IP address in the message text. Then you can update the message variable to say whatever you want it to. In the Help search for script and look at some of the examples. Two example files will provide a good start, Script_ContainsTest.txt and Script_ReplaceText.txt.