You're right. The 
Dim WhichTB1 as String
was left over from me trying ever conceivable thing I could to get the code to run correctly. The workbook I added was not my actual workbook (code cleaned up and stuff removed for privacy). I was comparing your code to my actual workbook (where I had remove the WhichTB1 code because it didn't do anything).
I mistakenly thought you added it and couldn't for the life of me figure out why.

This code makes so much more sense to me now.

Thank you.