My dad's job / hobby is the maintenance and installation / de installation of postboxes between Carlisle and Buxton . I saw this odd one on our recent Tideswell holiday which was one that he put in.
Previously I've come across few oddities such as this one in Worcester.
And then there's this similar one in Buxton which is probably another of my dad's.
And finally a Chinese style one in Stowell Street , Chinatown , Newcastle!!