ok I found it btw. The valvle that you posted a pic of is located on the right side under the 3pt lift adjustment, behind the right rear tire, roughly above the center of axle.
to orient the pic that you posted, it is made from a perspective if you where standing on the left side of the tractor near the floor board, looking to the right rear of the tractor.
I will post pics when I get home, just in case anyone else looks at this later.
I will also add nubers when i pressure test.