Can you tell me how the consecutive numbers are organized for the production runs and DSO options. MY Econoline has a VIN ending in "Q02422" Which looks to be the last of 1972's production it also has a special order DSO number of "1277" after the District code. (which I believe is the 1277th vehicle with Special Order Parts) Do those numbers refer to only the Econolines? the model within the Econolines? Or the whole production line in 1972? Any insight into how these codes were derived would be great. Can you look-up a model using the DSO code to find what it shipped with originally?