1.) VW=1952 6400 (2-ton)
The 0 in the 210 for trucks 2 and 3 should read as the letter O, or maybe even Q.
2.) The prefix is probably QK, as there was no OK. QK is for a 1947 4400.
3.) If this prefix is OW, it's from a 1946 first design 4500 series school bus chassis. However, for an AD truck, the prefix is more likely QW, which would be a 1947 6400.
21 is the plant code for Janesville.
