Keystone Spring Motor Boat Model #227 Breadcrumb Navigation Derrick Clow Published: December 13, 2013 Categories: Powered Boats Keystone Spring Motor Boat Model #227 This is a spring motor boat that is 16″ x 3.25″ (with the propeller guard). The propeller is made of brass. This appears in a 1941-1942 Keystone catalog. From my private collection.