Here are two suggestions I will offer but they are presented as "USE AT YOUR OWN RISK".
One would be to hook up an arc welder at very low amp setting by connecting the electrode end at one end of the rod and the ground clamp at the other - this will generate an electric current though the rod creating heat - similar to how they used to thaw out frozen water pipes years ago - the danger is that you could melt the plastic bushings, get things too hot and start a fire (please don't) and the heating may crack the cast pieces (not likely but 50 year old metal can do strange things. Would suggest cycling the arc welder on and off for 30 seconds at a time and then working the shaft back and forth and see if the heat is helping.
Second suggestion would be to drill a small 1/8" hole through the pivot points ( would have to drill through the transmission top over the steering column pivot and then the pivot at the rear pivot) and then squirting some oil into the holes and working the shaft back and forth. The small holes drilled should allow lubricant into the bushings without affecting the strength and could always be welded over if you ever decided to put the tractor back to original. I have attached pictures from when I redid my 1050 to provide you with a good view of what things look like covered up and uncovered. I would guess it is the pivot at the steering column that is causing the problem. I think ( but have not actually tried) that you can get an extension and socket up from the bottom underneath the tractor and undo the two bolts that hold the front pivot to the main plate ( I think they are 5/16" bolts with 1/2" heads) If you cannot get at them this way then you could undo the front drive shaft nut and undo the four bolts that hold the front bearing support plate on and remove it the same as if you were changing the belts. Then you should be able to get at the bolt heads with a wrench - it may be tight between the drive pulley and the main plate but I believe there should be enough room. If you undid them then it should allow you to move the rod and see if the rear pivot is still binding or if it is the one that is seized up.
Edited by 29 Chev, May 06, 2015 - 08:07 PM.