My source, not a very pimary one indeed , the book "Luftwaffe Markings" Barry Rosch the author, is usually pretty right , for the KGzbv1, he gave ;
Stab disbanded in Jan 1940
Stabstaffel disb. i. Mai 1941
i.Group with a complicated story, in fact long to transcrip
II.Group in mai 41 became FFS C6
III.Group who became the def. I.Group
Further I noted that the losses for 1942 are attributed to the KGrzbv172
A bit the same story as the one of the KGzbv108 downgraded to KGr.zbv108 after the Norwegian campaign
Rémi