Thanks to our friends at the Leicester Retro Computer museum, the long lost BBC AIV City Disc set has been found and documented for the Domesday86 project. This disc set (which is without doubt the rarest AIV disc made by the BBC) covers the square mile 'City of London' and was produced by the BBC's Interactive Television Unit in association with Citibank and the Corporation of London.
Details about the discs, including documentation, can be found by following this link.
A big thank-you to the Retro Computer Museum for making this possible!