Hi,
There's a 65 convertible E-Bay right now with sports mirrors, also a link on V8 in the ebay section.
Which mirror do you have now a remote or tri-shield?
They sell the Tri-shields and believe they work on both sides.
If you have a remote, there is a 63, maybe 64 remote that looks close and have seen on a 65 special years ago, the few I have seen on ebay were pricey.
Regard,