A few references to this extremely rare version of the system:

http://support.apple.com/kb/TA46839?viewlocale=en_US&locale=en_US

http://support.apple.com/kb/TA45090

The other specific problem is that the Mac will crash whenever it's connected to a network via AppleTalk. I have never seen an official Apple copy of this out there--I think most people wrote over those disks if they got two sets! (I do have a set of disks with the "6.0.7" label, but not the 6.0.6 disks that should be there too).

Hmm...I have System 3.1 (also extremely rare/buggy)...now I just need 6.0.1 and 7.5.4...