For those interested in pix of a drydocked WWII US Sub here is a link to pictures from the 2007 docking and refurb of the USS Pampanito that is docked on SF.
Link
She is a Balao Class but is still good reference for those building a Gato Class.
Iron Bottom Sound makes a conversion kit for the Revell 1/72 but to me looks very crunchy.
Link
Also there is the Fleet Type Boat Manual Here
More on the boat Here including more drydocking pictures (small pix)
Eric