Hi Trevor,
Keith has given you a lot of angles to ponder and I think you may now realise the near impossibility of a successful trace based on what you have - even if death was just the result of enemy action.
Might I just offer a word about armour plating? I believe that the only armour plating fitted to Lancs (as standard) was at the rear of the pilot's seat, and the pilot's headrest. that was all.
The only lightening efforts that come to mind were on the BI (Specials), where turrets were removed so as to facilitate the carrying the extra weight of Grandslam, Tallboy and Upkeep bombs.
As for distant targets, Bomber Command also ranged into south eastern Germany and attacked cities such as Chemnitz, Dresden and Leipzig.
Lancaster crew member? Well, there was the Halifax as well.
Best wishes,
Dave