I have used epubpress plugin for Chrome. The process is: go to the index page for the story and open new tabs for each chapter. Expand each chapter page by clicking the Click to load text button until all the chapter is loaded. When all the pages are open in their separate tabs, select the plugin and tick all the tab boxes (except the index). Click download. The resulting file is bereft of metadata and titled weirdly but Calibre is a great tool for sorting that. It beats copy and paste and produces acceptable ebook files.