Thanks to Paul Powels of Holland, we know now that this picture depicts the crew of Lancaster DV282 (BH-P), shot down by a German fighter on May 28, 1944 over Holland.
The crew: F/Sgt Jerzy Koziolek (pilot); F/O Witold Osika (2nd pilot); P/O William Tapp (navigator);  F/O  Wladyslaw Szymanski (wireless operator); Sgt Marian Myszor (flight engineer); Sgt Bernard Jankowski (bombadier); F/Sgt Ludwik Maciejewski (gunner) and Sgt Jan Duchaczek (gunner).
Please, contact me if You can associate names with these airmen faces.