At the weekend I spent a whole 1 on a 100 year old Brownie box camera.

The spool which was in it is unusual in that only one end has a slot which can engage with the winder. The other end is just a round hole.

I haven't seen anything like this before and wonder what the point is.

It is a plastic spool so I don't think it was the camera's original spool as that would probably have been either all metal or wood and metal. I also don't see how it could be the spool from a film as not all cameras run the film through in the sme direction.

Any ideas?