I vaguely remember something like this as a kid, a big loop of string was passed through the two holes, held by a finger at each end. It was spun, and by alternately stretching and slackening the cord, it could be made to spin first one way, then the other, emitting a whistling noise when rotating. I cant remember if mine was lead, but it did need to be fairly heavy material to provide momentum.
Had my first hammies of the year today, a very worn Lizzie halfgroat and an early C17 copper farthing.
Jerry