1971 280SL Gasoline question
 

I recently purchase a 1971 280 SL very nice condition, and
I was wondering if it requires leaded or unleaded gasoline.
The manual does not specifically explain this and not sure if they had Unleaded gasoline in that year. My concern is that if it requires I like to add the additive, since this may be lubricating the valves??. Also the manual says that it requires 96 octane?. Is this really needed. I believe this was a German design to be used since all is in Kilometers and has a 4 speed in the floor.
It has original 35,000 Kilometers in the Odometer

Thanks for any tips.

Al.