Personally I don't think that the number of vistas one owns determines the extent of knowledge... so I won't brag about mine....
The column or jacket as page 95 in the R-2154 Vista repair catalog refers to, should turn. What has likely happened is the lock pin has frozen its sliding hole. You can hope that penetrating oil will fix it, but a lot has failed for me on the terms of hopes and dreams.
Best bet is to maybe pull the dash and pull the steering motor assembly. This can be done by loosening the large tilt bolts on each side of the dash. (Anti-seize these during reassembly). Then go ahead and put the motor in the vice. Go ahead and take out the set screw and lock pin and lift off the column. Then, I would go ahead and take the rest apart to put a seal in the steering motor... but that's just me.
Ask questions and don't break stuff.. not much other than the seal is available!