I think I've got this figured out as to why nothing for a '47 3/4 or 1 ton matches your truck; it isn't a 1 ton, but rather it is a 1 1/2 ton Special. From about 1939/40-Early '47, there Chevrolet did not manufacture a true "1 ton" truck, other than a "1 ton Special" which was a 1 1/2 ton chassis with light springs, single rear wheels, and was only built with a very large Panel body. But I have heard of a 1 1/2 ton Special with the same equipment that used the standard bodies. I beleive that's what you have. From what I can tell, there's an extra seal that has to come out to access the lock and adjuster nuts
http://chevy.oldcarmanualproject.com/shop/1942_47/4247csm412.htm.
