If you can find a dark (camp stove) green, Surly Karate Monkey, that's about as vintage as it gets. I've read the KM was the first mass produced 29'er on the market. There were presumably custom 29'ers leading up to the KM but I doubt it was more than a handful of years.

Mine is a 2008 and is a 1st generation KM and looks completely modern. The KM is currently on it's 3rd generation and has substantial changes to the tubing and geometry. The first two generations had the same geometry with minor differences like top tube angle and 2nd gen KM's have a bracing tube between the seat tube and top tube.