I got this info from another forum -->
"SMS will make you exact door panels for your 68 .. Not cheap , and may take awhile ( 12-16 months) . But they are perfect ! You have to provide them with the top rails."
I'm sure they can make them for a 1965.
1967 Chevrolet Impala SS convertible - Ermine White C1
1967 Chevrolet Impala SS 396 - Marina Blue FF
64 and 65 are two different generations. did you try Impala bob, sinclairs and hubbards, as well as harmons'? Those are the primary sources I can think of at first, believe opg is in the game now, too. Impala bob may have fairly good used ones, too, might want to reach out.
No luck finding them. They are not in terrible shape, definitely will last me a few years. Maybe by then someone will start making reproductions. In the 10 years I have owned the car it is surprising how much more stuff is available now. I think people I getting into 65 Impalas more now because they are eaiser to come by than Camaro and Chevelle.