42-23521 - crashed, Palermo, Italy, 12th Oct '43
42-47382 - dest by bombing, Maison Blanche, Algeria, 16th Nov '42
Palermo would be a long shot in my opinion as there's high ground in the background on all but the eastern side but the photo was taken on a hazy day so it remains a possibility.
Maison Blanche was hit regularly during November '42, the 97th BG lost a number of B-17s there during the month, there's a few photos on fold3 that show the results:
http://www.fold3.com/image/47306877/The ground is similar to that in your photo so it is also a possibility.
There are also the following to bear in mind as they were ex-8th TCS machines that were transferred to the 4th TCS:
43-49530 - dest on ground - hit by B-17, Foggia, Italy 12th Apr '45
42-24333 - dest on ground - hit by B-17, Foggia, Italy 12th Apr '45
42-92683 - dest on ground - hit by B-17, Foggia, Italy 12th Apr '45
42-93784 - dest on ground - hit by B-17, Foggia, Italy 12th Apr '45
42-93785 - dest on ground - hit by B-17, Foggia, Italy 12th Apr '45
The 4th TCS usually applied a diamond to the top of the rudder instead of the diagonal stripe on the machine in your photo Neil but maybe this machine never got its diamond....
This story is very interesting IMO:
http://www.dc3airways.com/people/nash.html