'34 Fords had the serial number in 3 places on top of left frame rail--one in the vicinity of the steering box, which is the only one visible with the body on the frame, one about halfway along the length of the frame, and one on the arch over the rear axle. It is also stamped on the bell of the original trans case above the clutch inspection window, but of course you're not running the original Ford toploader. Ford did not put the serial number on the body. There is nothing in the serial number that indicates the body style. You should just have an 18- prefix if it was a V8 car originally or a B- prefix if it was a 4 cylinder car. The rest of the number is just a sequential production number. The serial number was actually assigned to the engine/transmission unit, not the car. When the engine/trans unit was bolted into a chassis at the factory, they copied the number off the trans case onto the frame. The stampings will be a bit uneven because they were literally hand stamped by a guy with a hammer and a set of number stamps.