Pan American Airways   Sikorsky S-36   4567        (c/n  6)

                                          

                                                 This rare old bird was actually the first of the Sikosky amphibians (or amphibions as they
                                                 were first dubbed).   Only five were built (despite it's c/n being # 6) and it is possible that
                                                 only one was used by Pan Am.   It was basically the prototype for the much more successful
                                                 (and far more numerous model S-38).