There's a picture of a P-39 in the picture request forum with serial no. 17246, which falls within the serial range for the P-39F, but it has 6 exaust stacks instead of the usual 12. Does anyone have any info. that can explain that?
In the Detail & Scale book, it was mentioned that some F models did have only 6 exhaust stacks per side.
I have also seen photographs of F models with only 6 stacks.
The only real difference between P-39D and P-39F was the propeller was Aeroproducts instead of Curtiss Electric.