Also you can do

fn h2d { echo 'ibase=16;' print `{echo $1|tr a-z A-Z} |bc }
header=`{dd -bs 1024 -iseek 128 -count 1 -if /dev/sdC0/fossil | xd -b | sed 1q}
bsize=`{h2d $header(8)^$header(9)}
super=`{h2d 0$header(10)^$header(11)^$header(12)^$header(13)}
dd -bs $bsize -iseek $super -count 1 -if /dev/sdC0/fossil | xd -b |
	sed '1,2d;3s/^.......  .. .. //;4s/^.......  (.. .. .. .. .. ..).*/\1/;4q' | tr -d ' '

to get the most recent one, though I like nemo's way better.