Hi Phil,
I only discovered this site last night and have now registered to answer queries. I am also a Derrington from Australia. In 2006 with the help of a Brummie friend from Aldridge we found the site of the old Manor House in Manor Lane Yardley. We purchased a book called 'Images of England, YARDLEY' put out by Birmingham City Council Department of Leisure and Community Services. I got my book from Bl;akesley Hall Yardley. On page 38 there is a photo of the Manor House with the photo being taken circa 1920, but it is earlier than that as I have a photo taken in 1918 by my uncle, who was suffering from gassing in France and was recovering there, with more vegetation around it. There is info on Josiah etc. I discovered more in on Josiah recently. There is a fountain memorial to him and his wife in Yardley Old Park (part of Yardley Conservation Area). It has a new plaque to the Derrington Family and the Rose Garden was formally renamed in his honour. I think the work was done in August. Google it. Josiah would have been an uncle to my late father. Like you I am still working through the Derringtons. I have a broad line family tree, but haven't slotted Josiah and family into it yet. I also took pictures of the new (1961) buildings that now stand on the old site of the Manor House. Once we got orientated the area was easy to find as there is an original house still standing on the right in both photos. I don't know if I am allowed to post my email address ( you would probably know) as I would like to compare findings on the Derrringtons and to also send you copies of my photos. Derro (Neil)