Unfortunately for you, there is no explicit delineation of that doctrine from the beginning. (We obviously disagree on the meaning of John 6. I don't hold your interpretation to be invalid, just incorrect. In other words, both interpretations give account of the evidence at hand. You think yours does better. I, mine.)
But, apart from the statements of Scripture and your accompanying interpretation, you have no oral tradition that explicitly delineates the doctrine (in fact, one has to wait a bit to even get it in writing). When someone asks for the oral tradition (and this is the entire point of my challenge), we are told to look at the Tradition. They are not equal. Your Tradition has developed, oral tradition does not. Your Tradition is not "from the beginning." Oral tradition was. Your Tradition equals Roman Catholic doctrine. That's not wrong. It's not even bad. Tradition brings stability and structure. I am not against tradition. But the claim that Tradition is equal to the oral tradition of the early church is unsubstantiated.