I would check McMaster-Carr for a rubber bushing that will work. I can't imagine they won't have something that will work. It may take a bit of searching. I would post a link, but I'm not exactly sure what the part(s) would look like. Maybe post a picture?

Matt

1969 CT90 - All stock, but not for long
1977 Triumph Tiger - Mostly stock, other than changes made by the PO