If you look down through the log file you should be able to find entries in the log for the other two tapes which are used. They don't show up as much as the initial entry since that also lists the media set etc information, but they are there.
If the tapes are labelled sequencially, eg 4mm0000x, or lto0000x etc, then you could try searching through the log to find the other two entries, and save yourself hunting through the entire log.