It's a Formula, and no the TA's didn't start their lives as one. Just another Firebird model option. Think Zump meant Firebird. Often get guys asking if they have a TA or a Firebird. Not unusual to have all the TA panels added, especially when they were far more common at the time than the other models. Likewise, a front end bump that required new panels would be far easier to source TA than original, but not impossible if they wanted to, and often they don't.
Nothing legit about custom Dymo stamped label on glass. Add some more pics if you like, check the cowl for options stamping but won't have many, being a VN build, check the door sticker to see if it still has the VIN readable. Engine and body numbers stamped matched at one time, less telling decades later without access and engine swaps etc. Pic showing front end has no decor trim on fenders and hood may indicate a complete panel swap more than simply trim being removed.
How did you go with the brakes?