Fingerboards were homemade toys in the 1970s.
The first footage of fingerboarding was captured in the film "Future Primitive" where they were fingerboarding in a metal sink. (See 1:45 mark) "Future Primitive".
Fingerboards were originally utilized as keychains for skateboarders, but became more relevant to the general public with the invention of the tech deck in the 1990s.
Now, techdecks are used to fingerboard on plastic skateparks or become part of a collection.