Build sheet trouble

So I found a build sheet in my car. It was under the back seat. Problem is, it is only 2 inches of one. So I need to know where else I can find another. It was on the very end and the rest was not there so I am thinking maybe the other part is on the upper rear seat? Please help

Here is a picture of all that I found under the rear seat of my 1967 Electra convertible.
Maybe Buick didn't use a "build sheet" in the same way the other GM marques did. - Bill

This might be what I found because mine had the punched holes on the side too.