Sorry 'GD' but I left in '68' - pre Indy - but at that stage we were running F1, F2,and Can-Am. From just the 4 of us at the begining, the team count was then about 25 (give or take a few).
I often think back to the days at Coopers when there were 3 of us mechanics for 2 cars, and that was from build to race track (anywhere in Europe). A few years back when there was refueling and tires at a pit stop, there were 25 over the pit wall.