Passing 73085. RCTS history records indicate all the remaining Stewarts Lane BR5's went to Nine Elms in May 1959. Either the date is wrong or the transfers didn't happen until later. Same comment applies to some of the Continental Boat Train photos.
Alan Goodwin has been doing some research and has found evidence of 35015, 73041/2, 73081/4/5/6 working on the SE after 14/6/59, so it looks like the transfers were delayed.