The friction pulley for Whites & Kenmores is still being made....& is easy to find! Here's one place to order it
http://sewing-machine-parts-store.co...&brand=&page=2 ....last one on the page.
This ebay seller also has them.
http://www.ebay.com/itm/NEW-KENMORE-...item43b1e92f0a
It's a 1/4" shaft & the rubber wheel has a 3/4" OD.