PLANE INFO:
The plane in the show was (most likely) a Grumman G-21A (affectionately named "Goose" by the British). The Goose was intended to be a rich man's toy, but proved so useful that it quickly became the plane of choice for many private maritime and mercantile concerns. The Navy and Coast Guard maintained a small fleet of Geese as rescue craft for many years, although I suspect that these days most of those duties are carried out by helicopter. Although the Goose has been supplanted in popular use by later planes in the same mold such as the Widgeon, Albatross, Seabee, and Mallard, it is still a versatile and popular plane, and still flies in the Caribbean and Alaskan islands. Also, it recently appeared on the cover of Jimmy Buffet's book _Where is Joe Merchant?_.
Its modern descendant is the McKinnon Turbo-Goose, which is basically the same plane with more modern accoutrements. Sadly, I don't have much info on that plane.
The Goose first went on the open market in 1937, with a base price of $60,000. A fully restored Goose is on sale right now in Kissimmee Florida for roughly $580,000.
There is a completely restored black and yellow Goose in vintage condition on the main floor of the Smithsonian National Air and Space Museum in Washington, D.C., which has a display showing where you can find Geese in use and a film of a Goose taking off, in flight, and landing in the water. (This may very well be stock footage from _Tales of the Gold Monkey_... it's been a while since I saw the show.) There have been model kits of the Goose produced in the past, but they are very rare and hard to find.
On the inside, the Goose was about the size and shape of a Volkswagon Bus, with a separated cockpit and an additional storage space/lavatory in the tail. It could carry five or six people in relative comfort, but no more than eight, and then not very far.