It appears we have a unique (and therefore priceless?) pressing of the disc 1 accompany AGU Research Series 68 (not 69 as I mistyped in my msg body, sorry, that would be too ironic).
AGU assures me our copy must have been a prank.
The accompanying book has an appendix chapter "Description of CD-ROM digital data...", by J.R. Childs et al., pp. A287-A296.
Some of our files match what is described there, some don't.
Hopefully we can source a replacement disc so future budding Antarctic scientists won't be unexpectedly surprised.... thankfully the 'bonus' content is legal (and now historic (late '80s) in terms of photography, bouffy hair styles etc.).