The Hydraulic Control s/n is located on the left hand rear face of the tank assy.

MAK154, yes I forgot to put in the valve on top of the cylinders, it is 2 hoses/steel pipes and I think 6 bolts holding to cylinder end, depending on machine the spool will be out of place in the valve or down the lines to hydraulic control valve trying to reach the reservoir/tank.
The later D10 the spool would end up jammed in the hydraulic control valve either bypassing like your machine or jammed in the spool not able to move the blade control all together. Removing the D10 valve is a day job in the hell hole done a couple of times.
I hope you have some good luck on your side and find the moved spool stuck in the cylinder valve or fitting close by.

There is no cir-clip used on this version and the valve body is held on by two bolts. The valves are retained by the line flanges with a "caution warning" about parts falling out when flanges are removed.