I believe the early 50's series were a little bit lighter than the late 50's. My '56 was also rated at 16K, but with the dump package it can carry 21K gross and is 9,300 empty.
The GVWR on the i.d. plate of 16K was the GVWR off the production line, but then future dump trucks go to a finisher that adds the dump box and swaps out the axle/s & springs to a heavier set. That puts the actual GVWR up around 20K, and of course it all adds weight, so depending on the actual box on the truck you'll be lookin at 8-9K tare weight.
Oh, and as for the 2-ton thing, that USED to be the approximate carying capacity for factory trucks way back when. Any more it's a size/class rating as obviously most any new 1/2 ton truck can cary a good deal more than 1,000 lbs.
I found these links that explain a little bit better:
http://www.autotropolis.com/wiki/index.php?title=Truck_Tonnagehttp://en.wikipedia.org/wiki/Truck_classification
