PTO shaft wobbling

I was going over my pasture with a brushhog on my 1952 8N this morning when I noticed a "clunking" noise in back. I stopped and saw that the PTO shaft coming out of the rear of the tractor has a wobble to it. You can easily move it about 1/4" sideways and up and down.

I've been using this tractor for years, so it's just something that's recently worn out, a bearing or a washer maybe? I rebuilt the motor a few years ago, but I've never been into the rear end of the tractor before.

I notice that the PTO shaft is surrounded by an access plate with bolts securing the plate to the housing. Is that how I get into it to fix the problem - and what do you think the trouble is?
Thanks.

I removed the Allen screw from one side of the ORC and the Zerk fitting from the other side, but can't drive the ORC off. In looking through those little holes, I think I see a small hole where the grease from the Zerk went - but there's nothing on the opposite side where the Allen screw was.

I've never actually put an ORC on, but I assume the PTO shaft has a spline around it just like the brushhog drive attaches to on the ORC. Whatever ring or pin from the ORC goes in that spline must be stuck, broken, or worn out. The spline on the PTO shaft may be worn, too. I'm hoping it's just a worn-out ORC, though.

At this point, the ORC spins freely on the PTO shaft by hand, and it wobbles sideways real loose. Any suggestions for getting it off? Thanks.

In wiggling the shaft by hand, though, it seems to me that the ORC is solid on the shaft and the whole shaft is wiggling. No oil leak, though.

If I park the tractor with the front end 'way downhill before I pull the shaft, can I get away with NOT draining the 90wt oil?