Absolutely, positive I have the right tape. The long story is:
This tape is from December. Since then, I had upgraded to 9.0. However, I kept receiving tape drive errors with 9.0, so I removed it, and reinstalled 8.6. Before I reinstalled 8.6, I attempted to restore from the tape and was able to see the Mailboxes, but I couldnt restore because of the tape drive error. So, here I am with 8.6, a good tape, and cant see the data I need to restore.