A reader pointed this out in a comment on an earlier post: The Fairchild A-10 Warthog. If you’re interested in the A-10, it’s worth a look.
Meanwhile, here’s a picture I happened across eslewhere:
This appears to be the demonstrator Night/All Weather (N/AW) aircraft, which was built by converting the first development aircraft. A Weapons System Officer would have manned the second seat, much like in the F-15E Strike Eagle. The N/AW A-10 was never produced.
What I’d really been looking for when I found the two-seater image was a picture of the A-10 in the good old green “Charcoal Lizard” colors: