Grommet and any other rubber pieces on old motors

[R&DMACHINIST]

I found grommets for the high and low speed knobs but think they are a bit overpriced and have decided to make some molds..Does anyone know what kind of rubber these lil dudes are made of...I work in a state of the art R&D shop for one of the biggest and most well known company's in he world so Im fairly sure I will be able start producing some of the hard to find stuff so long as I can get some specifiction help from all you great minds!
Thanks