Dave
A shot in the dark here, but Rotherhithe docks are only about 4 miles from Camberwell, the first reported location of Camberwell Beauty in England. Perhaps it is postulated that hibernating CBs arrived on timber at Rotherhithe?
"This is a central American species and a single specimen was captured in 1936 in a greengrocer’s shop in Rotherhithe, east London. It is believed to have been accidentally imported in the pupal stage amongst bananas, the specimen being attributed to the Jamaican subspecies delila."