[Marshall V. Daut]

I would imagine the change was in December of 1929 with the other 1929 models switching over to 1930's at the same time on the assembly line. I seem to recall reading somewhere that the Cabriolet (which debuted in May of 1929 and was very expensive) was a poor seller. Ford had contracted with Briggs for a certain number of bodies to be made. But by the end of the 1929 model year, there were many doors and quarter panels left over from Cabriolets that were not ordered. So rather than change to the newer 1930 body panels and doors and eat the older 1929 panels, Ford simply used these pieces for the 1930 Cabriolet, which ended up being a better seller than the 1929 Cabriolet. That's why only the cowls are different, the 1930 featuring the newer exposed gas tank with smooth-flaired moulding design commonly seen on 1930 Model A's. Naturally, the hoods are not interchangeable between 1929 and 1930-31 Cabriolets. The 1929 Cabriolet takes the same hood as the Fordors, Town Sedans and the Town Car.
The Cabriolet Club could probably be more specific about when 1930 Cabriolets began production, if that December date I suggested is not correct.
By the way, Murray and Briggs did not both make the Cabriolet bodies, as stated in some otherwise reliable reference books. The Cabriolet was only made by Briggs.
Marshall