OK, here it is:
Economic Left/Right: 6.75
Social Libertarian/Authoritarian: -1.64
I disagree with some of the positions of their site. But it's odd to see NO WORLD LEADER whatsoever on liberal democratic quadrant.
Anyway, I don't think the Pope is a leftist, much less authoritarian. Considering he fought communism for a large period of his life, that seems unlikely.
I also don't think Mandela is as much as a libertarian. Hitler should much more to the left, due to the anti-capitalist aspects of national-socialism. Stalin should also have maxed the authoritarian score. Some of the other ones they measured also appear to be way off.