Your cars birth certificate-the build sheet.

[cjk374]

I haven't found any papers for mine yet. I have had my headliner done years ago, so that leaves seats & gas tank.

 

[REGAL8r]

Found one yesterday in one of my luxury sports.it was stapled to the lower 1/4 panel insert.

 

[565bbchevy]

I found my 83' Monte's under the back seat, none on top of the gas tank and if I had one in the headliner then ASC probably removed when the power sunroof was installed.
Mine came with the CL package and had some nice options like the F41 suspension.