And for those who say there's not enough difference, bull honkey.
The 1A would be faster than the 1D with at LEAST the same acceleration/climb--if not better--due to less drag and slightly less weight. 1A vs 1D would be rather like the difference between the FW-190A and F that we have now (one dedicated to air-to-air, the other leaning more towards air-to-ground).
Plus, it'd open up ALL those F4U-1A skins (Boyingtons planes, the Jolly Rogers, etc).