ahh yes, if you read the question that way...
B17ggp1 - gunner position one
B17ggp2 - gunner position two
i think thats the naming convention, it escapes me here at work
there would be a sight for eveyr position in every plane, even though some have hard point sights like the waist gunners, and the gunners on the ju88. there are still gunsights you can "map" to them, they just dont show up