You might be right. To be honest I thought the same. However many of B&W images indicate the prop center could be painted. What is more, most of pictures that show French F4U-7/AU-1 at the early service with the prop hubs and the caps there solid coated with the Sea Blue. The French sources suggest these prop caps of a Light Blue, Red and just the White depending on a squadron or Flottile. There was only one shot I've seen, with the prop center that looked like bing of the NMF entirely. Here a couple of shots with the coat tone seen ... please pay your attention to the first shot below. The difference between the NMF of the prop hub and the tone of the prop cap can be noticed exactly.
Also I found a couple of colour images that reveal tha the prop center was of white undobtedly. In addition I would like to make a focus on the white numbers on the fuselages and wings that peeled off at many areas what might indicate not too very good quality of the paint. And this is the reason that let me believe the prop center was of white that peeled off.
It is always difficult to state what colour it could be if there isn't a good shot of a detail painted. But I'm still saying it was the white applied over the Sea Blue and peeled off.
Wojtek is right about the propeller hub colors, 12F was light blue, 14F was white, 15F was dark blue and 17F was red however, I have seen pictures of 14F with a dark color and 15F with white. I found a photo where both 14F and 15F were on the same carrier and both had white. As I mentioned earlier, these aircraft swapped squadrons frequently so I'm thinking changing the colors wasn't high on the list. It seems that 17F was perhaps the only squadron that was constant. Back to Wojteks photo I believe he is right as "710" was with 15F before it swapped to it's final squadron, 14F. That would explain the chipped white over dark blue.
Many thanks for the offer Andy. I'm going to wait for the model to show up and have a look at the decals to make sure they are the same as the previews I've seen and measure them to make sure the serial numbers are 8". If the kit decals are the same, I can mix the serial numbers together but will be short 2 white 8" 0s in stencil form (if this makes sense). I will go through my stash as well.
Here is a pic while owned by Heritage Aircraft.
I used to work for the owner who bought from Blaine Fowler. Its n-number was N811AP. It still had the Black Sheep Squadron paint job which was incorrect but showed better on tv. It was sold again a couple of years ago.