This last U.N.C.L.E. motion picture was made up of both parts of "The Seven Wonders of the World Affair" (1/8 & 15/1968), the series finale to The Man from U.N.C.L.E. (1964).
The yacht Solo and Kuryakin land the helicopter on is the "Wild Goose', the yacht once owned by John Wayne. It began its life as U.S.S. YMS-328 for the U.S. Navy. It is a wooden-hulled yard minesweeper built in 1943 and served in Alaska in WWII. It was decommissioned in 1946 and sold to a private party in 1948. Wayne bought it in 1962 and kept it until his death in 1979. It was purchased by Hornblower Cruises in 1996 and as of 2020 is still in use for private dinner cruises.
Although Kingsley's headquarters are supposedly located high in the Himalayas, the control building of his complex is quite clearly the Theme Building at LA International Airport.
The red and white helicopter Kuryakin lands in the desert is a 1963 Bell 47G-3B, registration N73959, which was canceled in 2013. This same helicopter can be seen in The Name Is Mannix (1967) and Only Giants Can Play (1969). This same helicopter is used by Kingsley in this film, with a "K" on the canopy.
The helicopter that lands on the yacht is a 1958 Bell 47G-2, registration N3105G. As of 2020 it is in the collection of the Classic Rotors Museum in Romona, California and is still registered as airworthy.