Hmmmm, there were at least two Timeless Tests which were drawn because England had to catch the boat home. I supposed that's what you'd call a managed retreat....
Not a link to the data but a link to the BBC weather news which shows that there are Hurricane force winds forecast for certain sea areas:
http://www.bbc.co.uk/news/uk-26153889
Lundy, Fastnet, and the Irish Sea
the junction whose geometry fascinated you is Lewisham, looking towards Charing Cross/Victoria. The lines to the left going over the bridge which fell down in the 1957 crash head towards Victoria and were originally reinstated in the late 1920s as a freight only line (previous alignment had taken the route towards Greenwich) and the lines to the right slope down towards St Johns.
At the far end of the overbridge is the Tanners Hill Flydown (recently doubled).
from where the photo is taken (Lewisham station) lines run to Hayes (with a connection back to the main line) on the left and Blackheath on the right
You may be right with your original note - Britain remained on BST for the period October 1968 - October 1971.
and thanks for posting all the excellent photos on your various threads