(20 Jan 2022, 4:09 pm)peter wrote The 763/764/773 are Durham County Council services. Go North East don't operate them because they either haven't bid for them or Weardale have a cheaper bid. Weardale have had them since at least 2008 according to VOSA but possibly longer.
Was operated by Classic Buses prior to that going off a quick Flickr search.
763 is a more recent introduction.
There's also the commercial service 765 between Crook and Consett at the start and end of the day (M-F)