I've just bought a copy of this excellent book from the author Charles Elwell. He apparently has about 20-30 copies remaining. I'll be happy to supply his address to anyone researching their Elwell Family ties. He is not on email as far as I know.
The book traces the genealogy of the family from 1327 to 20th century focusing on the male line and in particular the descendants of William Elwell (b 1736) who was mayor of Walsall. There are also some details of Elwells who emigrated from England.