I taped (just a hand-held) MacColl & Seeger singing this in 1968. They called it "The Cuban Revolutionaries" then. It's still in my head and I use it for Cuba Revolution Day in the "Happy!" file but I've never seen the actual words for it before.   Thank you.

The ABC is a pretty good rendering of the way they sing it, the which they do very well.

There's also MacColl's own loving song, "Che Guevara" which they sing on At the Present Moment.