I think what ever you do will be great. It is hard to describe what is in your head sometimes so I m glad you could follow.
I like the vine idea, I would call them roots instead and my thought is no leaves. I think they may not look right with the rest of the piece. To forged. To me would look like filler or to much. Just my take. But I do like the thought of using wrought and wrapping around the center pole to the base. Keep the simplicity and character of the old stock. You want a good symmetry between base and top. I think the leaves would brake that up. But just my thought on it.