Were the static collectors an RPO or were they part of the dealer installed static straps package?
Yup, every GM car got them in those days - they were installed on the Chassis Line. They were only supposed to go on cars with radios, but there were so few without radios they just put them on all cars. Any car that's had a brake job in its life probably has at least one missing. Corvairs used a special one on the left front that had a square hole in the steel "button" to drive the speedo cable.