The early 110 with galvanised capping, which was fitted after the body was painted, meant these rivets are unpainted . The vehicles with painted capping were painted as a whole vehicle set with capping's already fitted ,so any rivets were painted as well , On Series vehicles, 110 and Defenders these mid section panels, fitted on the angled area to the rear of the rear side doors was always fitted on final assembly ( After all the painting) and the rivets were not painted . They often get painted after accident damage or other repaints. I had a vehicle hit the side of my early 110 and was very particular to point this out to the repairers to make sure they were not painted.