Now I get it.
Part # 30 in the photo below.
There is nothing wrong with that breather.
What is wrong is the lower seal #28 has failed and is allowing PS oil to escape past it and overflow the lower half of the box.
You will need to dissemble the upper half of your column and replace BOTH the lower one #28 And the upper one #44.
And replace 2 orings #32,
Yes, you will need to pull the tin off to get at the column and yes you really do need to get at least the I&T FO-20 manual and read how to reassemble everything. Manual is available from this site for about $30.
Call your local New Holland dealer and order part #s 83929295 - upper seal
251310 - lower seal
87150s94GV - Orings X2
About $30 in parts.
Holler if you need help with reassembly. They are pretty simple but guys do have trouble with them sometimes.