Credit to LouS and quoted from :
http://forum.tz-uk.com/showthread.php?207616-Zenith-stars"Re: Zenith stars
My understanding of the logos as follows
to mid-late 1960's:
Dial - five pointed star
Crown - Z-in-five pointed star
Buckle - plain or Z in five pointed star
mid-late 1960s to 1971 or 72
Dial - five pointed star
Crown - four pointed 'NATO' star, also usually found on the caseback
Buckle - "ZENITH" written out on buckle
of note, some rare dials, usually simple three handers with or without date, did sport the NATO star - it is not clear how these fit in.
1971 or 1972 to 2000
Dial - square logo
Crown - square logo
Buckle - square logo
ever since 2000, five pointed faceted star on both crown and dial"
Hope this answer some of the many Zenith's sign on crown, dial n backcase.
