reading old tapes

[Neil Joseph Schelly]

I've got a pile of old Travan tapes at work with unknown contents.  Before I 
retire our last machine with a Travan drive, I'm trying to make an honest 
effort at recovering any potential data on these tapes so that I can figure 
out if there's anything valuable on them.

I can use dd to read the tape device and just looking at the data, it's 
clearly a backup of some sort, but I can't identify the type. Amanda doesn't 
seem to recognize the drive type, tar/bunzip2/gunzip all can't recognize the 
data.  The file program just reports that it is data.

Has anyone ever had to identify tape contents without knowing how it was 
written?  Have I missed anything obvious here?
-N