This is the Ealing tithe map of circa 1840 [can’t think of the exact date off the top of my head].
This shows clearly that the western section of the Swan’s Neck has been filled in/ silted up. The remnant is now recognisable as the Soaphouse Creek of today. Johnson's Island by this stage cut in half.
Apropos, a renewed application to get official residential status for moorings here to be residential has just been filed.