[wrndln]

I doubt the car is a 1930, if it was built in September of 29. However, the engine may not be the original one that was in the car when built. Someone probably in the past swapped the 21" wheels for 19" wheels. 30 and 31 model A's had stainless cowl bands near where the hood and cowl meet. There are a myriad of other differences between 28/29 and 30/31 A's. Post a picture of the roadster so we can see what it looks like. In one second most people familiar with model A's can tell the difference between 28/29 and 30/31 A's.
Rusty Nelson