G. B. W. Gay was the London manager of Brentano's, Publishers and Booksellers.
Brentano's, for which Gay worked in London, publicised itself as a firm of publishers, booksellers, importers, stationers, music dealers and newsagents. They were situated at The Round House, 430 The Strand. They also had branches in Chicago, Washington, New York and Paris.
In 1890 Gay was in correspondence with JW with regard to Sheridan Ford's pirate version of The Gentle Art of Making Enemies, six copies of which had appeared in Brentano's in Paris. However, none were sold.