> > It is probably best for you to dd the disk into a file on another drive,
> > so you can be sure you won't corrupt the filesystems with a Mac disklabel.
> > 

If you can get somehow(manually decoding disklabel) partition information
and dd partition to file, you should be able to mount it thru vnd.
Correct endianness should be taken care by proper ffs settings.
Just a thought.

Andrey