Restoring a car without documentation

Recently I scored the 68 Formula S, 383 Barracuda in this thread. Unfortunately the fender tag and build sheet are MIA. The fenderwells were cut for headers, then replaced completely at some time before I got the car. There was no build sheet under the back seat or on top of the glove box either. My last hope is in the headliner, hopefully I'll get to pull that down sometime this week.

Anyway, is there anyway to find out what options it came with at this point?