The A-10B was a two-seat prototype, proposed to the USAF first as a trainer, then as a night/all-weather attack aircraft. Only one was built, but the USAF actually ordered a few, but then cancelled them. Had they been built, they might have looked like this.

81st TFW, RAF Bentwaters, USAF s/n 82-0695, European I camo.

510th FS, 52nd FW, Spangdahlem AB, USAF s/n 82-0700.

Luftwaffe, JaboG 38.