I think if I was going to build a loader I would try to get some prints to go by, even if they were not for your particular tractor.
I built a posthole digger for my tractor and had taken tape measurments from a commercial unit.
I was surprised when I finished the unit and it did not lift properly. it would start to move and then would pretty much go out of control until it reached the limit of it's range.
I finally got it to work correctly with the help of a friend who has been working on farm machinery for many years. The adjustments to make it work were within the range of what was built in but would seem 'backwards' to at least my eye.
I would seem that there is some sophisticated geometry involved with these machines.