:You may be interested to know that there is a new book coming out soon which examines the Speyer case in detail - Banker, Traitor, Scapegoat, Spy: The Troublesome Case of Sir Edgar Speyer, by Antony Lentin (ISBN 978-1-908323-11-8). The foreword by Sir Louis Blom-Cooper considers that Speyer was very badly done by as were his wife and children and that the decision to remove his citizenship was not in the spirit or the letter of the law and was vengeful and lacking humanity. 

 :It is unlikely that a public apology will be forthcoming more than 90 years after the decision, but it does offer an alternative view from the public record.