I recently purchased a '61 861, when I received it the transmission was way overfull causing leaks from almost everywhere. Once I pulled the check plug and drained it down (about 2 gallons) the leaks stopped. I then had the PTO shaft out to replace the rear seal which drained all the diff and hydraulic fluid which got replaced with new when I put it back together. I recently noticed the transmission started leaking from the side of the case (slotted screw below left foot board). When I pulled the check plug about a half gallon of fluid came out, coincidentally my hydraulics were about a half gallon low. This has happened twice in the past few weeks. I am guessing there is a PTO (or other) seal between the transmission and the hydraulic case that is leaking hydraulic fluid into the transmission. I can not find a drawing or any info anywhere about this or how to fix it. Any help is appreciated. Thanks.