Does your Scout II wander?
The cause of much of your tracking problems may lie in the fatiguing of the frame at the steering gear.
The stress loads caused by the way the engine mounts to the frame and those imposed by the steering gear over the past 30+ years or so results in fatigue of the frame to the extent it becomes an unsturdy mount.
To check this, have someone turn the steering wheel and watch the steering gear (it will probably wobble).
Also, if you experience major handling problems in a crosswind, this may be your problem.
The "Track Straight" Brace eliminates this problem by stabilizing the mounting of the steering gear. Improving handling to the point you will be able to tell if the steering gear is worn.

Steering Box Brace (Track Straight)
	Quantity in Basket: None Code: SSBSII Price: $114.95 Shipping Weight: 12.00 pounds Sorry, we are currently sold out of 'Steering Box Brace (Track Straight)'. Please check back later.
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Steering Box Brace (Track Straight)

INSTALLATION INSTRUCTIONS:
1) Remove nuts from the two front bolts on the steering gear.
2) Remove reinforcing channel and bolts.
3) Position brace between frame rails and align with existing holes in opposite rail.
4) Install original bolts through reinforcing channel on the outside of opposite frame rail.
5) Install new bolts on steering box.
6) Torque steering gear bolts & nuts to original specs.
7) Tighten other side snug so as you do not crush the frame rail.