It seems like erasers made of vinyl or other synthetic ingredients are the norm today. Here is a traditional rubber eraser that I was surprised to find.
It seems relatively dense, and with a lot of particulate matter exuding from a new eraser. It does a good job on a Lumograph 100:
The paper in the photos is loose leaf 17 x 22cm Clairfontaine Séyès, an unusual sighting in Canada.