I'm 90% confident the original build records exist in a similar form to the A9X records as published in Eric Blair's Torana book. But if they do it'll be like shipping containers full of A3 size z-fold (tractor feed) paper and I seriously doubt anyone is going to go looking for original trim line info for anything short of GTS350's or L34's etc. Just to find the right pile of papers would probably take a day alone. Plus if they are pre-production records, for some assembly plants eg Pagewood they won't be sorted by any numbers on the car as Pagewood didn't allocate the PSN or chassis numbers until the very end of the assembly process.
What would be nice would be to find the original IBM360 digital files and somehow re-read them into a modern IBM machine. Then finding any car would be a piece of cake. But only a pipedream!