The three small floats look like tip sponsons from an amphibian plane -- Seabee or some such thing. Imagine what they'd sell for today!
Bensen wrote an article in the PRA mag about an uncommanded dive he experienced in the Gyroboat. It foreshadowed the stability problems we have had with body pods on gyros when the tail surfaces have not been designed with a pod in mind.
Those were Seabee wing floats, the Seabee was to be sold for 2500 dollars and orders were taken and production started but cost quickly climbed to several times what they had taken money for, they did their best to fill the orders but went broke,