[2] In 2001, Manley funded a multi-million-dollar renovation of the American Numismatic Association's (ANA) museum and library.

[2] In 2007, Manley donated a copy of Illustrium Imagines, the world's first illustrated numismatic book printed in 1517, to the ANA.

[12][2] In June 2006, he was appointed as the national manager of the Jockeys' Guild,[13][14][15] a position he voluntarily served without compensation for a period of one year.

[16][2] As a sports agent, Manley also represented all-star Karl Malone of the Utah Jazz[1] and negotiated a $66.5 million contract for the player.

[17] Manley was also known in the sports world for his role as the agent of NBA player Dennis Rodman during the 1990s.