The B17's information is as follows;
It was built in serial number run, 42-38084 / 38213 at the Long Beach Douglas Plant, and it's official designation was B-17G-30-DL Fortress, and it was from government contract number 8870/8999.
Missing Air Crew Report 3940, (MACR) can be seen at this link;
http://www.remember-our-heroes.nl/3940.htm , But it seems that Mr. Aonson was a S/SGT (SSG, Staff Sergeant today) and was the left waist gunner. I hope this helps.
I do have a contact at the Air Force archives that may have some records but that may take some time and there is no gaurantee they can turn up anything. About 8 years ago I found a crash site in the desert, researched it and found out everything about the pilot, plane, etc...