Tomy in the 1970s specialized in, among other things, wind-up toys with creative applications of standard wind-up mechanisms. They had creative wind-up vehicles and a line of wind-up animals called "Pocket Pets."

Here for sale is a collection of four toys:
A wind up train engine -- mechanism works, toy drives forward 
A wind-up plane -- mechanism works, toy drives forward and the propeller spins
A wind-up toucan "Pocket Pet" -- mechanism works, the toucan hops about. It is missing a portion of one foot but this doesn't affect function.
A wind-up duck "Pocket Pet" -- mechanism works, waddles side to side 

All four have functional wind-up spring mechanisms. In all cases the springs are not as tight as they were when new, but all work as originally designed. See photos for more details.