I usually search a site call Book Finder which searches booksellers all over the web. There are several titles by Madge Darby listed on Book Finder but not the one you seek. This is the first time I've ever Not found a title there. What I noticed, though, is that most of the books listed by the author were published in Australia or New Zealand. Perhaps a more detailed search on sites located in that part of the world (or perhaps in the UK as she seems to have been something of a specialist in all matters Wapping) might be in order.
