Those are hard to start due to the 6volt glow plugs, you can do a simple conversion to 12volt that helps it start much easier. The lawn mower battery gets drained too much with the original setup. Also those kubota Diesel engines tear up the drive shafts on those especially when the round rubber isolaters get worn, another thin I noticed is that the hood says it’s a 1512, but that tractor looks like the super series chassis instead which is a 1572 diesel. Due to their higher value someone probably took a 1512 diesel and a gas engine super series like a 1872 or 2072 and combined them to make the more valuable diesel super series tractor