I got the following from a post on this forum a while ago.
Don't remember who gave these instructions, so I can't give proper credit.
I made them per the instructions, and they work perfectly on my Farley... cost under $5.
" Since I don't have access to lathes, etc, I took the cheap way out on rail or rest feet. Went to Ace Hardware and bought 3 fender washers about 1.5 inch diameter with matching rubber washer. Then 3 smaller washers just big enough to cover the hole. Epoxy the small to the large over the hole. Contact cement the rubber to the bottom of the large washer. Tried them first at Raton and they worked perfectly. Total cost about $3.50 and about 30 min of time. On a smooth bench top you have to push really hard to move the rest, really hard. "