Older yo-yo’s were definitely smaller; in general. There is one, however, at the Yo-yo Museum in Chico that is pretty big 
Much can attributed to materials. As wood gets larger in diameter, the qualities that made it attractive diminish. Large wood yo-yo’s are a rock on the string and break easily.
Metal yo-yo’s also, tended to be smaller. This also was a historic and materials issue. As I remember, 54mm was the largest stock that certain CNC machines could work with.