According to GIFO G-AWSB was registered on 21/10/68 to John Richard Hawke who was better known as Jeff Hawke.
Many of the RAF Ansons which were sold off at that time landed up with “colourful” characters, some finding their way to Biafra.    

 Although it doesn’t relate to G-AWSB there is an old thread with some info about the Anson disposals here

https://www.key.aero/forum/historic-aviation/89894-biafran-anson?page=0