Jeff ,
It could also be an XE version , made before final production approval. "If" so , it would only have had a small ink stamped number on it. The "waves" would cause it to not be accepted by Ford. The other differences could have been requested too. "Every" part was at one time an XE numbered part before being approved. Fan belt to flex plate and oil pan to air cleaner. Though the parts were not meant to leave Ford , we all know they occasionally did.
Randy