SA oil problems, for Peculiar

Here's the only pics I have of my oil pump-





My situation was that I had an oil gauge that ranged from 0 to 30, and was reading '10'. My service manual says that an SA should have pressure between 50-60, so I guess I don't have the original gauge.
The '10' was worrying me, and my clutch was slipping, so when I went after my clutch, I did all new rod and main bearings while I had the engine off, as well as what I did to the oil pump, so I can't say exactly what made the difference with my oil pressure, but now my (wrong) gauge stays absolutely pegged on 30.
But I had no discernable 'slop' in the gears within the oil pump, but as you can see, the pump cover was worn, so I had a machinist mill it flat again.
I had two VERY thin paper gaskets that came with the engine-set. With one gasket, the gears were slightly binding, so I went with two, and 'called it a day', with happy results with my oil pressure. I've read plenty on this forum about guys carefully checking end clearance between the gears and the cover with plastigage, etc., so you'll have to listen to them, or get other advice. Those gaskets were, supposedly, .006 thick, so the difference between one or two wasn't much, and worked for me.
I'm not sufficiently experienced to be able to tell you why your oil pressure is (suddenly?) zero, but I'd be real careful running it until you find out why. I've heard that can happen with a 'spun-bearing', but there is a pressure-relief-valve in the oil pump, which is a piston with a long spring, and as the oil pressure rises above what the engine can use, the spring depresses until a bypass hole is exposed, and the excess oil is bled right back into the pan. It seems possible to me that if that spring is broken and the piston has dropped beneath that bleed-hole, your oil pressure will plummet.
Another problem I found with mine was that the original gasket had maybe a half-inch blown out, which won't help the pressure either.



If you don't know how to get the pump out, it's very easy, once you drop the pan. There are two bolts on the right side of the engine, you can see them right above the pan and maybe 6" directly below the oil filter canister. Remove those two, and with some twisting/wiggling, the assembly will come right out. Disassembly will be self-evident.
Be prepared to have to replace the old gasket(s) if you take the cover off. Mine was pretty decayed, what wasn't stuck.
If you don't have a service-manual picture, let me know and I'll post one.
You mentioned the 'heat' after plowing. I use mine to pull a brush-hog on hilly ground, and I was having trouble with the antifreeze boiling when I used it, to where I had to keep topping it up because it was going below the vanes in the radiator. During my overhaul, I added a waterpump, with the problem solved. Others here say it wasn't necessary. Worked for me.
I don't know what causes the blow-back out your breather. Hopefully someone else will explain that, and we can both learn.
Any other questions, stick 'em here!

Thanks for the pictures I haven't looked at the I&T manual yet but it should have all I need for repair & assembly. She doesn't seem to be overheating at the radiator but the oil coming out the breather concerns me.

Aw, heck with it, here's the pump, because I thought of 15 different things, now that the coffee has finally hit.

The round intake at the bottom is a FLOATING piece, so that it draws oil from the top of the reserve, rather than drawing the crud off the bottom of the pan. When the tube of the intake (sump) is slid into the pump cover, a cotter pin (which has to be of sufficient heft) goes through the hole in the 'boss' at the left side of the cover, and sits in the 'channel' of the intake's tube, which not only holds it 'captive', but allows it to swing, to sit on top of an oil level that fluctuates based on leaks and/or tilt of the tractor on a hill. If the swing of it is binding, or if the cotter pin fell out and the sump is sitting on the bottom of your pan, that will ALSO mess with your oil pressure.

Also, the four holes on the bottom of the sump could be crusted over with sludge, which could rob you of pressure.

Also, the helical-cut gear at the top of the drive-rod (which engages the camshaft) and the driven-gear at the bottom of that rod are keyed, and if a key sheared, you will also lose oil pressure. Two more things to check. The other gear in the pump body is an idler gear, but make sure it is healthy and spins also.

You can see the relief-piston and spring, and the hole in the boss on the side from which the excess oil goes back into the pan. The next boss up from that (there is another on the other side) is where the bolts go that holds the pump in the block.