This one-handed top change first hit the page in Jean-Nicholas Ponsin's Nouvelle Magie Blanche Dévoilée, 1853, p. 38, and later with illustrations in Jean Eugène Robert-Houdin's Les Secrets de la Prestidigitation et de la Magie, 1868, p. 186 of the Hoffmann translation. Ponsin described the move as a secret switch, whereas Robert-Houdin had an entirely different opinion; he thought the move was impossible to do without detection, and instead described it as an open flourish.
In Magic, Vol. 15 No. 3, Dec. 1919, p. 22, the change was described as the hand is tilted back. It was taught in a section dealing with secret switches, with no mention of this switch being any less covert. This section was a serial column called “The Dictionary of Magical Effects”, which dealt mainly with common tricks and methods of the period. Very few credits were given. The appearance of the one-handed change in this column suggests that the practice of the sleight as a secret move was known by this time.
T. Nelson Downs explicitly used the sleight as a deceptive one-handed top change. He described the move in a letter to Edward McGuire, dated March 21, 1924. (See The Linking Ring, Vol. 51 No. 4, Apr. 1971, p. 78.) His handling includes using a straddle grip. If his terse description is taken at face value, the repositioning of the second card is done while displaying the face of the top card to the spectator. (In a letter to McGuire dated January 19, 1924, he writes, “Elliott nor Houdini either one have ever seen or heard of my single hand top card change which is positively invisible on acc't. of the angle which obstructs the spectator's view at the time the move is made,” ibid., p. 69.) Presumably, the angle mentioned would be an oblique one that exposed the face of the top card and deck to a single spectator. The sleight, in this case would not be invisible to others, only to the one person.
Buckley described the sleight in his Card Control, 1946, p. 88, under the title “A Different Top Change.” He does not specifically claim credit for its invention. The details are vague, as is typical of Buckley's writing. He does not use a straddle grip, and apparently does the sleight “as the pack is raised up before a spectator,” although the timing of the move is not detailed, and must be assumed from this single statement.
According to Lennart Green on Green Magic Vol. 5, 2003, around 1968-9, Max Milton, of Sweden, also developed the secret one-handed top change from a description of the early flourish. He used a straddle grip and very constrained display action to cover the sleight: only a wrist turn; not a broad raising of the hand and arm. Later, Harry Lorayne published the sleight as The Ultra Move, in his Afterthoughts, 1975, p. 11. Lorayne acknowledged the “basic idea” had been discovered by Buckley and Downs. He teaches the sleight with a straddle grip, but mentions it can be done from normal mechanics grip. He emphasizes that the broad upward motion of the hand and deck are required for deceptiveness. However, though it is more demanding, Max Milton and others do it quite deceptively with just a modest wrist-turn.