Some of the Veco kits have been mentioned (Smothie, Papoose, ---) the list also includes the Scout, chief, squaw. Warrior, Brave.
F&B Super Sky Box.
American Model Entineering Co. (Johnny Casburn) -- Mis Behave, Little Cut-Up, Big Cut-Up, Super Over Easy, Over-Easy Jr.
Mercury Model Airplane Co - Flipper
Two versions, large and small, of the J.C. Yates Madman were available in kit form.
Berkeley Zilch came in three sizes - Mini, Lil-Duper, and Super-Duper.
The KENHI series - (Mustang already listed) Wildcan, Bobcat, and Couger
The Dave Day listing already posted above will probably have the most extensive listing of OTS kits, including those from Europe.
Keith