I still question if mine is a Formula S. 16 options on it. Has buckets, floor shift,center console, stabilizer bar, clock, bumper guards, Formula S trim panel on deck lid, F code 318
None of those options or items are specific for special for a Formula S. No 318 Formula S made.
If it's a 69, the deck lid trim has the S emblem swaged on it. Those get commonly damaged and get replaced or swapped out. And someone could have just added the emblem.