Hi J.J.
Thanks for the welcome

If Allison was the bomb-aimer, then that would seem to suggest that the chap on the right of the line is the navigator,i.e. Villneuve.( I remain convinced that Allison is third from right, on Burke's left.) No self respecting nav. would let his bag of tricks stray far, and that is definitely a nav's bag on the ground in front of the three on the right. Given that the man second from the left is the other gunner, that puts Hamel, the pilot, as the man extreme left.
Pure conjecture of course, but with what evidence there is to hand, I feel fairly confident that I'm somewhere near the mark.
I have, of course, just set myself up to be knocked down but, there you go!