We've now confirmed that Earl Stanley Cary was definitely the bomb aimer on the plane. He was also promoted to Pilot Officer just before he died (and possibly posthumously); up until his second last mission on 2nd August 1944, he was a flight sargeant, which creates a problem for us, as it means he has two service numbers! His first number (when he was still an NCO) was R143086.
While I haven't had much luck with Earl Cary yet, we do have a lot more information about how he met his end, so if anyone out there has an interest in his fate, there is now plenty to share! Perhaps more will be revealed when the service records come through. I've had a form letter and have been advised that this will take about three months.