If I recall the earlier alignment specs, there should be a certain amount of toe-in so when the car moves forward the road will force it outwards to take up any minor play in the steering. If the toe in/out is perfect then the steering can be prone to wandering, which what it sounds like you are experiencing.
Don, sorry to be slow to respond, but I'm still having to work for a living. What Mike said is exactly what I was "taught" back in the day. (Thanks, Mike! Your explanation is a whole lot clearer than what I was told in 1965...) I'm old enough to have driven several different cars on bias belted tires. They did not wander all that much with a little toe-in setting.
The alignment "specs" are actually for the car. As for tracking, the alignment was considered "correct" if they did track just a little to the right (outward). Or, again, that's what I was told the first time I went to buy a set of tires on my own. I did wonder at the time, if the English aligned so that they tracked to the left...