In the earliest days of Doctor Who the BBC’s Visual Effects Department didn’t have a great deal to do with the programme, as it was considered beyond their resources. As a result, effects would be handled by scenic designers, who often employed outside companies such as Shawcraft for special prop construction and model work. Contrary to the popular conception that effects on Doctor Who’s original run was handled largely in-house, this hiring-in procedure continued for several years.
Bill King ran The Trading Post in the 1960s, at the time of the company’s closest association with Doctor Who.
The Trading Post was used for visual effects on several stories during the Patrick Troughton era, although the company’s association with Doctor Who went back to the programme’s very beginnings in 1963. It supplied some of the set dressing for the TARDIS control room in the very first episode, and occasionally hired out other bits and pieces for various stories thereafter.