I think that it's mainly places on/near the north Norfolk coast that are readily considered to be in editorial Belmont-land (by BBC and ITV), as far east as Sheringham or possibly even Cromer (?).
King's Lynn is possibly the furthest-inland Norfolk settlement to be included.
I dunno whether the likes of Castle Rising, Dersingham or Little Walsingham are considered part of the patch? Surely not the likes of Fakenham though?
Isn't King's Lynn viewership divided between the Belmont ("Hull news") and Sandy Heath ("Cambridge news") transmitters' signals, meaning that no King's Lynn terrestrial viewers actually get the news programmes that you'd most expect ("Norwich news" / Tacolneston transmitter)?
The story of Phil the Greek crashing his car near Sandringham made both Levy Live and Calendar.
Parker and London Lite gave kudos