Hydraulic Pump/Top Cover and IPTO Help

Hello,
Posted earlier on the Massey Board but I have a couple, more general, questions I figured I would throw out here.
This is a Massey 165 gas, with IPTO and multi power.

Long story short, something does not allow the P.T.O. lever to actuate the P.T.O. and now it is stuck on, even though handle is in the off position, so I had to remove top cover to attempt to address the issue.

Problem #1: When removing top cover, I did not remove the roller from the control valve lever on the hydraulic pump. I was unaware of this...now I am.
I have the control valve lever, the roller on the top is MIA. The lever sits back in its natural location without problem. What I cannot seem to wrap my head around is what happens at the middle of the lever. There is a small flat plate with a hole in it that rotates around a shaft. Circled in green, picture 1. A small, indented piece of metal was also in the hydraulic oil when I found the lever after pulling the top cover. That seems to snap into that smaller hole. I can?t, in any reading, figure out what attaches here. If the flat plate were to face the engine side of the tractor, there is a hole in a plate which lines up and a tiny hole in the pump body about 6? away. This is indicated by hypothetical red line in picture 2. Is there a small spring or something there that I have yet to find?

Problem #2. The IPTO. The P.T.O. handle rotates a shaft which moves another smaller shaft up and down into the P.T.O. clutch. I assume that this turns on/off the hydraulic flow to P.T.O. clutch. It appears to be stuck in the fluid-off position. The up/down actuator only moves downward 3/8? or so and hits something solid. Internally, I believe there is a pin and spring and a small ball in there. Picture 3, circle in yellow. I removed the cotter pin from the collar but cannot get the collar to separate from the shaft. Back to picture 2, circled in blue. Any thoughts? I don?t want to force it....should I unhook the hydraulic lines to the P.T.O. lever cover so I can pull that mechanism out to give more freedom of movement to the lever/shaft assembly?

Finally: The tractor had some work done by someone else a year ago, and it appears, that when the top cover was put back on, he didn?t put a gasket on. Any argument for not replacing gasket when I put this back together? Unbelievably annoyed with myself here. Making a medium sized problem into an even bigger one. Pictures might be reversed order when posted.

Based on pictures I can find...that center piece seems to anchor to the plate...
Like I said, I have a small metal piece that seems to snap through it...but I?m not sure what would hook it in...I see small bolts in lots of pictures...
Does it matter? Should it be tight to the plate or should there be a little play in it?

The newer ones have a pin with a little clip. The later ones have a kind of grommet that snaps in. On the later ones I've taken to typing them in with wire. It should be pretty snug to the plate. There is a very tiny pin with two rollers on it that run the pump control. Hopefully they didn't come off. They're very hard to get back on from up top.

I kinda-sorta understand how the control linkage works.

It is a delicate adjustment, very little movement of the levers and roller, so everything has to be right. What was bent and sprung is anyone's guess.

As for the PTO, never been into one of those...

My best advise, invest in a shop manual. Much better to have the real story right there in front of you than trying to ask questions, wait for an answer, then decide if the answer was legitimate.

Does the snap grommet go through the plate mounted to the pump to the lever or reverse?
Yes. Rollers at base are intact and when I do I lever type action I feel the resistance of pumping. So I think that is good.

Do have a proper shop manual. Does not address either of the problems I am facing.