Massey 165 P.T.O. Disengage and Hydraulic Top Cover Issues-

I have a Massey 165 that received a complete overhaul a little over a year ago.

Least year, about 2/3 of the way through hay season, the P.T.O. began to shut itself off while using it. I noticed it a couple of times tedding. I looked
back and noticed I had dragged some hay for a few feet. I assumed I had hit a bump and my heel had knocked the lever or something, then it
happened again. So i figured whatever detent held the lever in place (when you engage it, you can feel the lever being heldwhen it is fully engaged)
was weakened. I thought, maybe, that the hole on the shaft that the pin which holds lever in had worn, leading to excessive play, which allowed gravity
to pull the lever down. So, I temporarily solved the problem with a wooden shim helping to hold friction on the lever, fighting the drift of gravity.

When I removed the lever, the hole in the haft was not wallowed out, and I noticed that the shaft which stuck out of the transmission did not stick out far
enough to easily get the handle on. I had to pre-curve the pin to attach the handle to the shaft and, again, it still drifted down. Based on what I read
online, I determined that I would have to remove the Hydraulic Top Cover to address this issue. I attempted to remove the plate that the P.T.O. lever
mounts to, but there are internal hydraulic fittings attached to it which eliminates the ability to remove the plate without removing the top cover and
fittings. I then avoided this task, as the 165 is my winter plow tractor and could not afford to have it down.

At this point, the P.T.O. no longer disengaged. The shaft would not fully rotate (move maybe 20 degrees) and the P.T.O. runs non-stop. It will not shut
off.

I opened the top cover yesterday and did not see the internals I had expected (which is always a fun sight, then you think you have a mental handle on
what you are about to see and then it is different). So, now that I can see, the P.T.O. lever cannot move to a positition to engage the detent. This is part
of what I don?t understand. From what I see, and please correct me if I am wrong, when the lever is moved to the engagement position, the shaft and
plate with the detent rotate clockwise until the little horizontal detent spring/plunger goes into a plate. When the lever does that, it pushes a collar
which is pinned to a shaft/plunger which actuated the P.T.O.. In my picture, this is what I have circled in yellow. This shaft, however, does not want to
move downward. It moves, maybe 3/8?. It does not appear to be frozen. I feels as though there is something jammed inside of there. If I remove the
pin to the collar, can I just lift the plunger out and see if the spring/ball are intact? Or am I looking at something frozen in place and it needs to be
coaxed into moving. What is the best approach here?

2nd question/issue.
When I pulled the top cover and associated part out, this yoke was floating in my oil. Circled in red/green in my picture. I see that it is a part of the
hydraulic lift pump. How/why would it have been detached? What type of pin holds it on? What impact does this part being detached have on
operation? It is weird since the hydraulics have been fully functional up to the moment I pulled the top cover. I am sure I will have mor questions about
this as I proceed but it has me stumped right now.

Final question/issue - do I use a gasket when reattaching top cover? Oddly, when I removed it, there was no gasket or gasket material. I expected
there to be and had pre-purchased a gasket to put in place...do I need it?

thanks in advance, sorry for the long/confusing post.
Thanks

Ok.
Some follow up from my 2nd issue with the yoke piece of the lift pump. I just found, online the diagram below. I think I understand, more, about my confusion. Correct me if I am wrong here, the piece that the yoke it attached to, should not have lifted out with the top cover. It does not mount to that, but, rather, mounts internally.
Right? Or wrong?

It appears that the floating part is called the control valve lever...which I should have removed prior to top cover removal.
In the picture from the manual, and my part in real life...there is nothing between the 2 holes which I have circled in green. Should there be a roller there or no? I had assumed yes...but the picture I see and the piece in real life has nothing...
2nd...where I have indicated red, the piece in real life is a little shinier there...I assume that it is held in place there...what is it held in place by and why is it long and slotted....is there some adjustment or is it just to get it in place?

I'm not much help on the independent PTO issue but as far as the roller is concerned. It is likely now somewhere down in the transmission case. So to answer your question yes you should have removed the roller before removing the top cover. With that yoke being detached you now need to get to the front of that 3 point pump to figure out what is wrong. I'm guessing with the roller still in it broke a pin or screw that holds it onto the pump. Now I'm unsure if there will be enough room to get your hand in there to work on it without splitting the transmission and rear case. My best guess is to work on that pump much more than a filter change requires the split. Splitting it at the transmission case might be your best bet to find the roller (its likely under the pump) and fix the pump. Now about the split. There is a line that runs from your auxiliary pump up to the multi-power valve. That line must be undone to split the tractor. When I did my 180 work I did a double split (Roll motor away, then use a hoist and split the transmission off the rear housing) which I feel would be easier than trying to leave the transmission on the motor.

Did you remove the pump lever roller BEFORE pulling the lift cover? Roller MUST be removed first, or linkage damage will result..

No I did not.
I went back out to the tractor and where the yoke sits on the pump is intact and moves in and out as it seems it should.
Are the rollers a common part? Where does it attach to the lift pump cover? I have the lift pump cover currently covered waiting for some bad weather to pass (shop is not the most well protected) so I cannot look now.
Also. Any idea how to remove collar from pto clutch plunger. I removed cotter pin but both pieces still move together.