Yes, the AU-1 was the last US production variant. Compared to a -1A, it would have the four bladed prop, engine cowl with "cheek" intake scoops, a frameless canopy hood, and armed with four 20mm cannon instead of six .50s. Also the wings would be fully metal skinned, and their would stubs for four rockets under each wing and three under fuselage hard points for bombs or drop tanks. It also was more heavily armored since it was built strictly for ground attack.
F is for FIRE, That burns down the whole town!
U is for URANIUM... BOMBS!
N is for NO SURVIVORS...
- Plankton
LSM