Although its abit late on i do have some shots from hayes and harlington, looking at my photos from about London, they do seem to be mixed in with other workings, some are mixed in with the crawley and purley portions to acton and onwards to merehead or whatley, some going out to Dagenham dock.
https://www.flickr.com/photos/trainsbysanchez/34214723034/in/datetaken-public/ one shot with what I believe the HOA's are.