Besides the VC label (door tag), there is also a code on the body buck tag and the assembly line broadcast sheet.
The body buck tag is 3.5" x 1.5" metal tag stapled to the radiator support frame, behind the driver-side headlamp. That tag was used by the assembly line to build the basic body. Dearborn Assembly changed the tags for the '88 model year, and I'm only familiar with the arrangement on the '87 and earlier tags. On the earlier tags there is a "TR" code on the second line for a T-roof. Not sure about '88 tags.
The broadcast sheet (also called the "build" sheet) is an 11" x 8" paper sheet with a bunch of codes on it. They were taped all over the outside of the body to help the assembly line build the car. They were supposed to be discarded at the factory but you may find one or two under the carpet, or under the rear seat, or behind the interior quarter panels, or on top of the gas tank, etc. But you may not ever find one for the car. Again, I'm only familiar with the early sheets but on those sheets, on Line A, there is an "H" code in position 23 for a T-roof.