Don't mean to be nitpicky, but that Stang in the picture isn't a 64-65... it's either a 67 or a 68, but I can't tell without seeing if it has side marker lights or not, as 68 was the first year for the side marker lights.

Anyway, the 64-66 taillights were contained in a chrome light assembly which was set on top of the rear panel, while the 67-68 all were recessed into the rear panel with individual chrome accents.
Here's a pic of the rear of my 1965 and you can tell the difference in the tail lights.
