With patience, I was lucky enough to find a used one too (engraved with Army unit markings). Not used very much, but not expensive either. I used it just like the TM said and am pretty confident I got the toe-in set within spec.
One of these days I'm going to take the truck to one of those computerized wheel alignment shops and see just how close I think I was.
So long as my local shop won't charge me an arm and a leg just to check the toe-in and measure the caster-camber angles with their modern lasers and computers, it's more just curiosity for me.
I'm pretty sure my toe-in adjustment is in the ballpark --- the jeep handles well. Too early to tell about abnormal tire wear, not enough miles yet.
The scale on this gauge is graduated in 1/16 inch (.0625) increments and the toe-in spec in the TM is between 3/32 (.09375) to 3/16 (.1875) inches. That's pretty fine measurement --- I had to re-calibrate my eye-balls.
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51
“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari