You are doing an amazing job with this. I have to chuckle a bit though. For many years the 64 was the less desirable of the two. Many people would put a 65 front clip on their 64 as well as switch out the interior so they could have the more desirable 65 look. In essence, a clone.
You are doing the complete opposite. 😃
I am fortunate enough to have a 1964 Elcamino body and grill. I also have a 1965 donor. My build will more than likely have a '65 "upgraded" interior. 😁