Up for sale here is this set of 3 brand new rubber grommets for mounting a turntable motor. These are in great shape and are nice and flexible. Dimensions are 1/2" diameter, 5/16" high, 1/4" inner diameter. These will work on a lot of vintage turntables and portable phonographs, including a lot of BSR gear.
US shipping and handling is $7, and international is $21. All my small parts are set up for combined shipping, so just use the "add to cart" feature and then check out all at once, and it will combine shipping. If you have any questions, please ask.
I have a number of vintage turntable parts and other vintage electronics listed--feel free to take a look!