[Spooks] 4XZ header analysis

[spirals]

Hi All, Some time in the past i came across an analysis of the preamble 
of the messages sent by 4XZ. I appear to have lost my updated copy due 
to a disk crash and backup that failed to restore hi!.  Can anyone point 
in the right direction which site it was on or better has anyone been 
doing this analysis and can get me back on track. any help much 
appreciated.

best 73s, Dave.