when became the Auto Drag wheels available?

I just looked over an old April 1975 car craft magazine I still have. Cragars, Ansens, Keystone and Appliance were advertised ,no Centerline Ad.
It is easy to differentiate the centerline from the Cragar by the rivit / bolt count in most old pictures.
Cragar used 15 fasteners. Cragars blue logo center cap on the front wheels was a dead give away also.
Centerline cap logo was black.