Sounds like that car's had a couple different owners, and at some point somebody swapped in those parts. With the vast array of repro parts out there for these cars, an owner can do just about anything they want (and fab the rest) to change the look of it to suite their personal taste, and since you know it isn't a GT, then at some point in the car's life an owner swapped the rear valence and put a new exhaust on it to match.
BTW - saw it was your first post, welcome to the forum. There's tons of info in here, and a bunch of people that know what they're talking about.
__________________ 2003 V-6 - the usual bolt-ons. Gremlin taking up residence in the idler pulley. I'll finish this one when I'm done with the other one.
1965 coupe - Born - straight six standard issue
Now - 5.0 motor, T5 tranny, R&P, full length subframe connectors, draglink bars, hedman headers
Coming soon - disc brakes, electronic ignition and a whole host of other stuff I forgot to mention. The list goes on and on. Basically, it's my new toy  | 
1965 Stock Exhaust Question 
The car didn't have that when it was brand new. That was one of the things that Ford did to visually distinguish a GT from a non GT dual exhaust car, like a K code that didn't have the GT package. 40+ years is a long time, though. People do all sorts of stuff to these cars. 
