Christos Zoulas wrote:

    Try scanning the disk for the ffs magic number every sector
    magic = 0x011954. Have the program print the sectors that
    it finds that, and then attempt to mount this. The tricky
    thing is to find the size of the partition...

I believe you will find multiple superblocks ("struct fs" in
/usr/include/ufs/ffs/fs.h) in each partition.  If I recall, newfs
tends to put one at sector 64 (63?) as well as sector 0.

Dave