On Fri, Nov 5, 2010 at 2:08 PM, Ethan Dicks <ethan.dicks at gmail.com> wrote:
  There's some guided trial-and-error needed, most
likely. ?If it truly
 is an "unknown" filesystem, there are two tools I'd start with to
 investigate what the image is about... 
Thanks Ethan and Dave McG!  I suspected it would turn into a bit of
forensics and sleuthing...which makes it more fun, even if it's a bit
more work :)
I have a lot of drives laying around that are totally unknown, either
because I bought/received them as spare parts or they were (foolishly)
removed from a machine that is now gone.  I'd bet I've got IRIX,
SunOS, Solaris, Amiga, Mac, DOS, HP/UX, VMS (those are kind of easier
to spot)...the list goes on.
Someday I'd like to offer data recovery as a paid service.  Sounds
like I've got a lot of practicing to do :)