The best references to speculate an answer to the question when was the first Victoria built is the new book by MAFCA, "The Victoria Book 1930 to 1931," and the record of surviving 190A's belonging to the International Victoria Association. Here are the dots:
> FOMOCO photos of prototype Victorias dated March, 1930;
> 36 production Victorias built by October, 1930;
> Oldest surviving Victoria is 190A0108. The reported frame number of this car indicates the 190A Body was assembled onto a chassis in April, 1931 which unrealistic. So either the body was switched onto a chassis other than the one it was originally built with, or that body sat around until April, 1931.