OK, I finally found one of the red "63" bugs. I say it's a late 66, but it isn't 100% correct.
It is sporting a 64-66 convertible deck lid. It has two sets of louvers which didn't show up on sedans until 70 or 71, so it's a convertible part. It has the wider license light and push button latch, which are 64 and up features. The profile of the deck lid changed in 67 and again in 68, so this deck lid had to have once belonged to a 64-66 convertible.
It is missing the half ring on the horn button. These were dropped for the 64 model year, but added back in early 65. Either the ring is broken off, or it's not the correct horn button.
If you look really, really close, it appears that the door handles have round push buttons. These were used for the last three months of the 66 models and all of 67. For several years before that, they had retangular push button. After 67 they had a "trigger."
The windows were enlarged in 65. I don't have another one to compair it to, but this one looks to me like it has the larger windows.
There was something different about the later low back seats, but I don't remember off hand what it was . . . are the seats correct for a '63 or for a '66? I "think" these are later style low backs.
I pulled the back seat up to read the VIN, but I couldn't get my head in the door so I couldn't read it so I'll have to just guess. After considering all the things above, I would have to say it's a late 66 . . . with a 64 horn ring and a convertible deck lid . . . and the wrong wheels. 66 should have had sloted wheels and these are smoothies.
OK Bugtech, tell us what you think it is and why.