851 Steering Issues

I have an 851 that developed a steering problem. This is a '59 model with manual steering that is not kept under cover. The tractor is 130 miles away on my farm where there is no cell or internet coverage so I have to look for information when I get back to town. Last fall while bush-hogging for deer season I noticed the steering had developed a lot of play. During hunting season I rarely have time to drive the tractor but do crank and run for 30 minutes every other week. About a month ago I was cutting a field and noticed the play had become worse and then suddenly was taking everything I had to turn the the wheel. While I had renewed all the fluids in the fall, I did not do the steering console. Limping back to the cabin the steering froze. No right turn and a little left. When turning the steering wheel, the steering shaft unthreads and backs out about 3/4 inch. I have the I&T manual but do not see how to pull the steering wheel. The nut is off but seems to be keyed. I pushed a long thin screwdriver down the keyhole and turned the steering wheel but felt no key. Before using a steering wheel puller, is there something I missed.
2nd question - with the steering shaft backing out while turning the wheel, what kind of damage should I expect?

bearings shot at the least , the wheel should come off with a puller
Boss

Similar situation on my 641 sometime back. Bearings wore out and fell apart gumming up the works. Wheel is probably rusted onto the shaft. Try some PB Blaster and a puller.

Thanks to both of you for the feedback. Since I had a little play pulling the wheel I was hesitant in using the puller until I reviewed the manual (which I conveniently left at the homestead). I hit it with KROIL before I left and will make sure I have the I&T manual with me when I go back.
I'm sure I'll have more questions as the job progresses. I have a '51 Farmall cub sharing the garage with my wife's Cadillac that had a stuck piston from 25 yrs of sitting. I've got that one torn down to do a ring job at a minimum so my weekends are occupied for some time.

Thanks again.