All Firebirds, including the Esprit, Formula, and Trans Am will have the 2FS87 on the cowl plate.
Fisher made the bodies, and they were all Firebirds.
Like I said, some Trans Ams got the WS4 with the codes alittle bit lower on the cowl plate, with the options.
That's why I think your cowl plate is probably the correct one.
Did you vertify the paint code to the car itself, or the build sheet?
George