A hole in the h-head!

No. I'm not talking personally, but in my '47 H. I'm down to attaching most all parts together now, and found I had overlooked a threaded hole center back of head by the air cleaner. Looks like it is about a 5/8 threaded hole. Old IH parts catalog sez it takes a "breather pipe, cylinder head to air cleaner". I assume it goes from head to top of air cleaner pipe in hexagonal hole ? Anyone know where I could find this part? None listed on Fleabay just now.
Thanks in advance from this duffis wanna-be Farmall mechanic!

The following were cut from caseih.com parts diagrams they include the correct components it is a PCV type breather system:

51434DX ELBOW ELBOW, cylinder head to air cleaner breather pipe, with nut, 278953R91 (Air cleaner end)
20 1 278953R91 NUT NUT, cylinder head to air cleaner breather pipe elbow (Air cleaner end)
20 1 278953R91 NUT NUT, cylinder head breather pipe connector (Cylinder head end)
21 1 51436DX PIPE, breather, cylinder head to air cleaner, with two nuts, 278953R91
22 1 57942D CONNECTOR CONNECTOR, cylinder head to air cleaner breather pipe (Cylinder head end) (Will work for 38026DM)
23 1 57942DX CONNECTOR CONNECTOR, cylinder head to air cleaner breather pipe, with nut, 278953R91 (Cylinder head end) (Will work for 38026DMX)
24 1 51206DAX SPARE PART TUBE, cylinder head breather, with two nuts, 369989R1
25 2 32252DX CONNECTOR, cylinder head breather tube, 35252D, with nut, 369989R1

Go to caseih.com. then parts and service, then scroll down till you find (in small red leters) search for parts. In the search box put Farmall. scroll down to H. Choose head and valve cover. Jim

Thanks a Million, Janicholson. I had no idea that Case-IH still supported a 65 yo. tractor!
I printed out my order, and will stop by dealer Monday.