Leo's Den are advertising a very interesting new CD to be released very soon, simply called "F.B.I.": https://www.leosden.co.uk/shop/index.php?id_product=2137&controller=product
Some tracks have never appeared on legal releases: the undubbed version of "Happy Birthday To You", the early take of "Guitar Tango" with Jet Harris on bass guitar, BBC radio versions of "Man Of Mystery" and "Perfidia", BBC TV performances of "The Frightened City" and "F.B.I." (both from the "Crackerjack" TV show), "Wonderful Land" from the Royal Variety Performance 1962, "More Than I Can Say" live in Copenhagen in 1961 and a selection of tracks from the Radio Luxembourg radio show "Me And My Shadows".