Gallowglass

Countess Gallowglass ran a message forwarding service for aliens and time travellers in the 1970s.

It was run from a Portakabin in the East End of London. By 2012, it was run from a well-hidden plushy building near Carnaby Street. (PROSE: Relative Dementias)

Behind the scenes
In the short story Commune, which appears in the 2003 fanzine Myth Makers 13, it was revealed that a colony of Time Lords have been living in an implant in Gallowglass's head ever since the fall of Gallifrey.