1- cockpit
2- nose
3- ball turret
4- tail gunner
5- top
6- left
7- right
It has been asked for, but this breakdown is not the best fit.
You need to start with the most common position, the mid-upper turret/gun, though you could call it the tail gun if you like. Basically, list out each bomber and figure out which positions match up. IIRC:
A-20G: Mid upper
B-17G: Mid upper, tail, nose, right waist, left waist, belly
B-24J: Mid upper, tail, nose, right waist, left waist, belly
B-25C: Mid upper, nose, right waist, left waist
B-25H: Mid upper, tail, right waist, left waist
B-26B: Mid upper, tail, nose, right waist, left waist
B-29A: Upper front, upper rear, nose, right waist, left waist, tail
B5N2: Mid upper
Bf110s: Mid upper
Boston Mk III: Mid upper
D3A1: Mid upper
G4M1: Mid upper, tail, nose, right waist, left waist
Il-2: Mid upper
Ju87s: Mid upper
Ju88A-4: Upper right, upper left, belly
Ki-67: Mid upper, tail, nose, right waist, left waist
Lancaster Mk III: Mid upper, tail, nose
Me410: Mid upper
SBD-5: Mid-upper
TBM-3: Mid upper, belly