Hi, Doug,
I don't know - I've never even driven a 280. I thought perhaps something had changed in the later cars, since they definitely have a different part. Perhaps it was just redesigned?
BTW, because my car was French, the ability to have the fog lights and headlights on at the same time was disabled. It took me quite a bit of tracing to find the circuit that accomplishes that, and put it back to "standard".
-David Pease
'66 French 230SL