The Artilleryman:
First, I would get the book, "Attack Bombers We Need You! A History of the 416th Bomb Group" by Ralph Conte. I am sure your neighbor would enjoy this book. In the back, there are a great many names of crew, last 3 of tail numbers, mission numbers, and more. So his name is most likely there many times.
Second, the squadron code for the 669th BS, 416th BG is 2A. The Group tail markings for the 416th was a white (or very light colored) stripe on the rear of the rudder parallel to the trailing edge on A-20s.
Third, and small world time, my first duty assignment in the active Air Force was Griffiss AFB, Rome, NY. That was the home of the 416th Bomb Wing. The 416th then had B-52Gs and KC-135As. So I am, in a small way, a distant part of his Bomb Group.
I hope this helps you in some small way.
Bill G.