How to have more infos about a car if the documents are long gone?

Hi Guy i have a deposit on a 69 gts 383 project and i might pick up a 69 formula s 340 at the same location....but the fender tag is half gone and theres no broadcast sheet for the barracuda....is there anyway i can find infos to maybe have a correct reproduction of the fender tag if its half gone ? Is there any way to know the other missing infos on a very bad tag ? Thanks a lot, both cars are rolling chassis and need total restoration.