When World Champion's walked among us like normal men

I'm currently evaluating software that processes pgn in bulk, doing a quick analysis of games using various chess engines. At this stage I am calibrating the results using older events where engine assistance (in opening prep) isn't part of the equation*
One event I am using is the Montreal 1979 Tournament of Stars. It was won by Tal and Karpov, and included almost all the top players in the world at the time. Tal started off the tournament with a win over Spassky, but the second most interesting thing from the game (after the moves), was the rating of both players. No 2800+ Super GM's here, just a couple run of the mill low 2600 journeymen!


Tal,Mihail (2615) - Spassky,Boris V (2640) [E94]
Montreal Montreal (1), 1979

*The reason being that it is a lot harder to differentiate between engine moves and 'remembered' engine moves when looking for evidence (or non-evidence) of engine assistance.