Don knows his stuff, if he says its a Kingsville, I would take that bet over any Internet guess from a photo. Remember young trees growing rapidly will have much bigger and broader foliage. Once bonsai techniques are applied and growth is slowed foliage will reduce and change shape some. Leaves may reduce to 1/10th the current size. Then it will look like an internet Kingsville. Right now your tree needs to grow, so keep it growing. You need foliage and vigorous growth for a few years to thicken that trunk.