Early take off square body tailgate

[Austinjay]

I am not sure the exact year this gate is from so any help is appreciated. The gentleman i bought it from said his dad took it off after the second day of owning the truck to put the camper in the bed. The only scratches is has is from the wood they hauled back to their farm on the way home from the dealership. Unfortunately it sat leaned up against a wall in the dirt floor of a barn for several decades. Just want to get some opinions on the value. I will be putting it up for sale when i can get a fair price. i can also send more pictures