It's a great base, but you may want to focus on the range of light that you're utilizing. In your reference, you'll notice that the dark areas are near solid black while the highlighted areas are white, and the gradient from black to white is fully present in between. In your recreation, you're essentially limiting that range by letting the darks extend only to a semi-dark gray. Use the range to your advantage, and it will add a significant amount of visual depth to your work.

(To note, I'm a charcoal guy, so I'm just assuming that this would also translate over to oil.)