Yeah, verily Mr npalen !
Fishwiz: I'm familiar with that area of the rear (top link attachment point) on Massey tractors. Your third photo (which gives more of a side view) shows a roughly 2" diameter rubber boot. That boot covers a shaft which goes in and out a very small amount based on top link loading. This is "top link sensing" for Draft Control. Some models (like my MF 2660HD) have a very heavy spring showing in that boot location.
No, it has nothing to do with adjusting the length of the top link.
I will not describe what Draft Control is (suggest you read the owners manual about it and if you lack one, they are no doubt available on-line.) Suffice it to say unless you are plowing or doing some sort of soil cultivation you have no need for Draft Control. If you are not plowing/cultivating you should find the best way in your situation to disable the Draft Control. It can cause unwanted 3pt lift behavior including some very weird ones that I will not describe here either. Just a PITA unless you need/want it for plowing.
You have 2 levers for 3pt lift control. The Position Control (used 99.999% of the time) and the Draft Control lever.
The routine way to disable Draft Control (DC) is simply to move the Draft Control lever all the way UP as far as it will go and leave it there or better yet fasten it there. [check your manual; that could be all the way DOWN on some models. It is all the way UP on mine.] That does not in fact disable DC but desensitizes it to the point where it has no effect except for some oddball situations like VERY large top link loads. Once you get the DC disabled then the Position Control lever raises your implements and works like everyone would expect it to. The other way to really totally disable the DC is to buy a kit from MF which mechanically anchors the top link attach point to the frame of the tractor (which I did.)
Note that yours has a pin (the head of which shows in all 3 photos) that goes through the shaft into the rear axle area for Draft Sensing. If you pull that pin, Draft Sensing is gone for sure (!) but then what restrains the top link attach point base from rotating ? Probably a different kit for the MF1190 than for my MF 2660 HD. Mine definitely would not work on your tractor.
So your options are:
1) Contact a dealer and see if MF is selling a Draft sensing bypass kit for the MF 1190. They probably do. OR...
2) Read the book and put the DC lever where it needs to be to disable DC most of the time. That's what most people do. OR...
3) Go the tinkerer's delight route, which is to figure out your own way to anchor the top link attach point base and keep it from rotating. That might require a little innovation but can of course be done. Your owner's manual may very well suggest how to do that or less obvious ways to disable the Draft sensing.
All good. No big deal. Have fun.
