DamienB
ACCESS: Confidential
Doesn't qualify as an "unbuilt project" but as only 19 were built before it was canned...
http://www.ebay.co.uk/itm/Seamew-Light-Anti-Submarine-Aircraft-RAF-brochure-/160651743417?pt=UK_Collectables_Militaria_LE&hash=item25679710b9
http://www.ebay.co.uk/itm/Seamew-Light-Anti-Submarine-Aircraft-RAF-brochure-/160651743417?pt=UK_Collectables_Militaria_LE&hash=item25679710b9