1/240 1939 US Submarine Conning Tower

I made this part to convert a 1/240 scale Lindberg model of a Gato Class submarine  to an earlier Porpoise, Shark, Perch, or Salmon Class. At the end I did not have decals for one of these boats, but I did have decals for the PT 109. This allowed me to finish the model as SS 190 (USS Spearfish), a Sargo Class sub. The differences of the conning towers between these classes are not very large. The earlier classes had two extensions kind of like rabbit ears to support the antenna wires in a particular way.  The later classes had a larger fairing around the periscopes.