The Ossulstone Hundred is a misnomer. The area of London of particular note for The Dee Sanction is not strictly speaking the Hundred, but a fraction of it that presses against the northern shore of the Thames. From Dowgate Ward to Tower Ward, the area encompasses the southern access to London Bridge as far north as Leadenhall Market.
However, this is not that London. The Dee Sanction is already an alternate take on history and in mapping out the areas, wards and neighbourhoods you should expect differences. Many differences. The map is being hand-drawn and then coloured. Beyond that, I’ll be marking up key streets and locations. The general sights and sites will be the same, but I fully expect, for example, that some churches might be the wrong shape, the guildhalls the wrong size, and the islands under London Bridge the wrong orientation.
That’s a fictional London for you, without being an utterly fictional one. This is a Tudor capital with hearty nods to a reality you can read about and expand upon through John Stow‘s travelogues, but don’t expect everything to be just so. As the Core Book indicates, the game isn’t about pedantry and the map isn’t either. This is not an exam; there will not be a test.