Kim ~ Kimmc found this company that supplies plastic bushings that he needed for his '60 Tbird convertible top mechanism. He used part number 2559409 on both his top frame and top cylinder pivot points. They have dozens of plastic bushings listed so they probably have some that will work in other locations. These are bushings that the Thunderbird vendors don't carry. There is no minimum order. As you can see from their main webpage, they have lots of stuff that we might need. Here's their phone number and website link. 800-645-7270.
Here is the link to that bushing page.