Leighton - I have a fair bit of info on this crew. My mother's younger brother was the mid-upper gunner, Sgt David Brewer. I was in touch with 'Wally' Wallis's family a few years ago and have a photo of him. Happy to share info, and would be glad of anything you can add. Sadly HK538 didn't complete a single sortie - David's diary says they got it new on 31 Jan.