Observations on rocker panel colors:
- on lighter-color cars, having the rocker panels body color makes the car look much heavier than when the rocker panels are painted, say, flat black over body schutz (protectant). It's my understanding that (almost all) lighter-bodied cars left the factory with the rocker panels painted (flat) black
- on dark-bodied cars, body color looks ok and may be the way cars left the factory
- for some reason or other, cars in the UK very often have the rocker panels body color, even on light-colored cars
As for the rest of the cars underside and the wheel wells, I was under the impression that they were always body color, even on light-colored cars. There's more information in older threads on this and probably also in the technical articles.
Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic