Tractor Repair: Water in the oil pan, head gasket, cylinder sleeves

Question
I have found a 1947 Farmall A and when I got it home there was antifreeze in the oil pan what could be wrong

Answer
  The head gasket could be leaking, the o-rings on the cylinder sleeves could be leaking, or there could be a cracked head or cracked block.  The head gasket or o-rings are the most likely.  Remove the oil pan and see where it drips from.  If it drips from inside the sleeves, the head gasket could be letting coolant into the cylinders.  If it drips from the outside of the sleeves, the o-rings are leaking.