I have an old radiator that was taken out of a '69 Fastback and I wanted to verify if it was original. There are some numbers on the side, but they are hard to read. From what I can see, it looks like the part number might be C8ZE-L1. Does anyone know if this would be original?

The reason I ask is because I have someone interested in buying it. He restores mustangs for a living and would have a pretty good idea what it would be worth, I don't have a clue. All I'd be interested in is a fair price. Any thoughts?