Yes, the VIN number on the build sheet breaks down like this:
1 = US
G = General Motors
2 = Pontiac
A = Seat Belt system
X = Firebird S/E
87 = 2 Door Coupe
L = 2.8 Liter HO Engine
1 = Check Digit
E = 1984
L = Built in Vany Nuys CA
212x85 = Production number
If you also look at some of the other codes on the build sheet, it backs that up as well. For example, the engine code is a LL1 which didn't start until 1983 and in 1984 it signified the 2.8 liter engine. Same thing with the transmission code of MD8 and the turbine wheel code of N24, the W69 code for a S/E,and so on, and so on. So yes, the build sheet came out of a 1984 S/E Trans Am. It is wierd because the color of the car was a Light Briar Brown Metallic car with a dark Briar Brown interior. Of course the two most important parts of the build sheet (the upper left and upper right hand corners) are missing which has the VIN and cowl numbers and also the date produced, but as you can see from the rest of the build sheet, it is for a 1984 Firebird and not a 1981.