Have a look at the website below hosted by the National Art Library of Scotland.
The link will hopefully send you straight to Biggin Hill. If not, you can zoom in and find it. Make sure ‘Side by Side’ is clicked at the top.
At top left, you get a drop down menu of maps through time and you can compare them side by side with present day satellite images from google earth with pinpoint accuracy. Using this enables you to see where Cudham Lodge stood from the 18th century. It was swept away at the end of the First World War to expand Biggin Hill. You can even see a shadow on the ground between the runways in a shape that partly matches the map.
You can also see the layout of Aperfield Court where the first wireless transmitter was built. This too was demolished but its giant cedar survives in Aperfield Road and is marked on the map as early as 1888.
Have fun …