The website sfarad.es just posted this biography of Hakham David de Sola Pool. Unfortunately is in Spanish only, but I think it provides very interesting details.I was surprised to read that, at least according to the author, the ashkenazi community in NY did not consider the Ottoman Jews who were arriving to the USA in the early 1900's as actual Jews. Hakham de Sola Pool was working to help them. The biographical note also mentions the edition of the Ashkenazi siddur by H. David and his works to finish the Sephardi siddur. https://www.sfarad.es/r-david-de-sola-pool/?fbclid=IwAR07yTzL263ek5DESHODrtq1LfywCaWFtzPVkRezbdjSJSAs9iPcnHH0kR0