Given the CJ-5 on the sign, it is safe to say that this isn’t earlier than 1955.
“Rare True Barn Find. Mid 1940’s Willys Jeep Dealership Sign. This Piece of Collectible History spent most of its life in an old barn in Oklahoma as a horse stall divider. 95″ Length x 46 1/2″Width. $1750.00 OBO. ”