Hi Alain check for David Brown Tractor club forum they seem to cover the part about hydraulics quite well this would be your best way forward as far as your plough is concerned do you have discs or skimmers for your plough, if you have fit them. on a starting point with your plough is put it down on level ground adjust the top link until the plough is sitting level. when the plough is level and the ploughshare tip is on the ground and the heel of the plough is on the ground you should be able to put your fingers in a hollow between the two if you cannot your ploughshares are worn, I hope this gets you started I will take pictures on Saturday and post them on line it will give you a better idea Keep well