When Ash makes a presentation on Adam Rice there is a photo of a newspaper article on him by "Jo Portman". Jo Portman is a journalist-turned spy from the TV series MI-5 (2002), which Hustle's creators also produced.
Marc Warren's character Danny Blue is portrayed as skittish about skydiving. Warren had previously played Easy Company member Albert Blithe in "Band of Brothers" and underwent jump school as part of his preparation-- including a forty-foot harness jump from a mocked up airplane.
After Micky is shot, Stacie seemingly phones for an ambulance. She gives the address of Eddie's Bar as Change Alley, EC1. The outside of Eddie's Bar is in Change Alley, with its real post code of EC3.