I took my own advice and emailed the British Library.

This is the reply:

"I'm afraid that I haven't been able to find any further information about the author of The Fairy Ballad Book, Endymion's Dream and East and West; or, Alexander's Death, all of which have been published anonymously. If this information was readily available I would have expected it to have been recorded either in our catalogue record, or in the catalogue of the Bodleian Library, Cambridge University Library or the National Library of Scotland (all of which hold copies of at least one of these books).

This may be a bit of a long-shot, but I wonder whether the archives of George Bell & Sons, the publisher of The Fairy Ballad Book, might help to shed further light on the identity of the author? The National Archives' Discovery platform suggests that material relating to this publisher is held at the University of Reading Library's Special Collection's Department ( http://discovery.nationalarchives.gov.uk/results/c?_aq=George%20Bell&_dss=range&_st=faadv ), so it might be worth getting in touch with them for further advice: https://www.reading.ac.uk/special-collections/ "