Adding to JayJay's comments:
All '30-31 Model A's had a hole in the inner brace that runs across the cowl panels. These holes were for cowl light arms, if the body was to receive cowl lights. Otherwise it would have been a nightmare on the assembly line to determine which bodies were to have cowl lights (either standard or specially ordered) and which ones were not, and then drill the hole as needed. It was smarter to simply have a hole in each bracket, whether it was to be used for cowl lights or not. I'm not sure looking at that hole from inside would tell you much. If you are lucky, the wooden block between this brace and the cowl panel will still be present if the car had had cowl lights. This little block of wood kept the cowl panel from collapsing as the large nut on the cowl light arm was tightened. If that block is still there and looks really old, chances are it came from the factory or dealer that way - although some restorer may have added it in the past. In that case, the block would look newer.
Unless your car was stripped down when you got it, there are other ways to tell if your body came with cowl lights, at least based on what was supplied with each body style. Dome lights in the deluxe and upper-priced sedans was oval shaped and was located between the back two wooden cross bows, above the rear window, while the standard models had a round dome light located over the rear passenger's feet. If your body has the oval dome light, it most likely came with cowl lights, which were standard equipment in the higher-priced "luxury" sedans. The oval dome lights had a toggle switch on the center post, so you should see signs of a cutout in the wood for the switch, as well as the remains of wiring running from the dome light in the rear to the terminal box. The round dome light, on the other hand, had a simple on-off lever in the light itself. The wiring for this style would only run from over the passengers' feet to the terminal box.
If the interior garnish pieces were woodgrained instead of painted, that's another indication of a deluxe sedan style that would have had cowl lights.
Any original interior left intact? Although not conclusive proof, the more expensive sedans with cowl lights had more luxurious upholstery than the standard models without cowl lights. Mohair was the norm in these higher-priced sedans, although just about any interior in the Ford line COULD HAVE been ordered. The 1929 Murray Town Sedan, for instance, had the standard body style grey check upholstery offered as an option in addition to mohair. If your body has any mohair upholstery left, it was most likely a deluxe, higher priced Model A that would have had cowl lights.
Center arm rest in the rear? Although variations have come to light, the deluxe sedans had a folding center arm rest in the rear, whereas the standard sedan bodies did not. If your car has a center folding armrest, it probably had cowl lights.
Finally, check the quality of the hole drilled in upper cowl panel. Is it uniform and drilled cleanly or sloppily drilled? If the latter, someone may have not had a large enough drill bit to make this hole for the cowl light arm. Signs of filing the hole larger with a rattail file or jagged edges would be a telltale sign that the lights were installed by a "restorer".
Well, all this should be enough to help decide if your car had cowl lights originally. Does it really matter, though?
Marshall