by dave-r » 19 Jun 2001 19:32
There is some disagreement over this but this is what I think after lots of discussion on the subject when this message board was somewhere else.
A body coloured flush fitting cap was used for 1970-4. The flip-open chrome type was optional (standard on some models) 70/71 only. Replacement gas caps were flush fitting chrome plated so that the owners did not have to get them painted body colour.