The tractor is very interesting, but the sun-dappled foreground pulls the eye away to featureless turf, and the background is too clearly visible. Ideally, you would have waited around until the light was perfect, and then shot with a wide aperture to blur the background. Another way would have been to shoot with an off-camera flash to provide enough light to reduce the effect of the ambient, and this could have served to put more light on the tractor.
Another point to consider is your placing the tractor in the center of the frame. That works well for an illustrative shot, but is less attractive for a story-telling shot. One option would have left a bit more space in front of the tractor to allow us to image the tractor "driving" into that space. Another framing option would have been closer up, focusing more on the exposed part of the engine.
These old machines have so many potential picture possibilities - it is probably worth you while to try different angles and perspectives to highlight specific elements.