Good find, John!
The video mentions Brennan's monorail car. But that monorail used a gyro (actually a couple spinning in opposite directions) with the axis horizontal, instead of vertical like in that toy. It had an ingenious mechanism to "speed up the precession" and return the monorail to vertical. Crabtree's book has several pages dedicated to it. The toy version, the "Gyro Mono Car" shown on Lourens book, appears to have the gyro vertical, like in the Gyro Cycle Top, but I would like to know for sure. A toy that had something similar to real Brennan mechanism would be really cool.