Mr. G might have what you need. You'd be amazed at all the oddball stuff he has. Scale pictures of fasteners on his site. He'll also look at pictures you send him if you can't find what you need.
Automotive fasteners, of all types
Mr. G's Enterprises
5613 Elliot Reeder Road
Fort Worth, Texas 76117-6013
817-831-3501 or 817-838-3131
https://mrgusa.com/
