We found these Models (Exploded Views):

Picture of GH2750

GH2750

Gitzo off centre ball head, series 2
Picture of GH2750QR

GH2750QR

Gitzo off centre ball head, quick release, series 2
Picture of GH3750

GH3750

Gitzo off centre head, series 3
Picture of GH3750QR

GH3750QR

Gitzo off centre head, quick release, series 3
Picture of GH5750QR

GH5750QR

Gitzo head off centre quick release, series 5