Here's some info on the two Revell kits, courtesy Dr. Thomas Graham's fine book, Remembering Revell Model Kits (pp. 99-101):
"One of the world's pioneer environmentalists was Jacques Cousteau, whose TV show 'The Undersea World' was a fixture on America's television screens. Popular folk singer John Denver had just recorded a hit song about Cousteau's oceanic research ship the Calypso. Dave Fisher originated the idea of making a model of the Calypso. Cousteau's son Philippe lived nearby at Marina del Ray, and Fisher approached him about the possibility of a model that might be a fund-raiser for Cousteau's conservation society. Philippe replied that the Cousteau Society did need financial support, but that a 'toy' would not be dignified enough for association with the Cousteau name.
"Undeterred, Fisher arranged for a breakfast meeting, with Royle Glaser [then chair of the board of Revell, and widow of one of the company's founders, Lou Glaser] and Jacques Cousteau joining the negotiations. Fisher explained to the elder Cousteau that Revell's model would be educational and would include a booklet explaining the mission of the Cousteau Society. This meeting broke the log jam, and Cousteau signed a contract agreeing to funish the information necessary to make models of hi ship and amphibian airplane. Mrs. Glaser came away from the meeting impressed with both the handsome Philippe and charismatic Jacques. 'I've fallen in love with Jacques Cousteau,' she announced to the staff back in Venice. 'He's brilliant and charming.'
"Fisher flew off to Monaco and Toulon, where he visited Cousteau's museums, and then to Greece to measure and photograph the Calypso. The resulting model incorporated lots of nifty details like Cousteau's two-man diving saucer, a helicopter, a Zodiac boat, and a shark cage with two tiger sharks. The Calypso flying boat was a modification of the PBY model, molded in white plastic with Cousteau Society decals. Royle Glaser thought the pair of models made a great product idea, but, like most civilian planes and ships, it turned out that they didn't sell well. Then Philippe Cousteau died in a crash landing of the Calypso aircraft, and Revell decided to pull the plane model from the market."
Dr. Graham's appendix lists the original (and only) release date for both kits as 1977. I rather suspect the market for the Calypso is, if anything, even smaller now than it was back then - especialy in view of the anonymity Revell Germany seems to be imposing on it. My suggestion to anybody who wants the kit: grab it while you can.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.