I haven't seen a Kubota (I do admit an imcomplete knowledge of Kubota's, not trying to be a smart alleck) with a front axle set back that far- it looks like an orange Yanmar, to me. Given the front axle placement, and the frame, my novice eye would say Yanmar.
Well, I do love learning new things. I looked up some photos of B1600's, and they do look alike. The axle is set back, the tractor uses a frame, but the ones I saw had 6 lug front wheels.