Hi GW, welcome to the asylum!
Is the steering still real stiff with the front wheels off the ground? If so, the two places I would be looking first are the control head, and the idler arm.
But if lifting it makes it seem fine, my first suspect would be the steering box. There is a bushing down in the bottom, item 2 below, that has to hold the shaft 15 in line, but the shaft is only supported at one end. If the bushing gets worn (often as a result of no lube), the shaft can tilt when steering force is applied and then the peg 15a will bind in it's slot in the worm, 4. The drawing doesn't make it clear, but the peg has straight sides that match the straight sides of the groove in the worm pretty closely.
Unfortunately, the box has to come out to replace that bushing, which means removing the front apron and associated components. I have managed to do it without removing the apron, but IMO it's easier to pull the apron.
PS, that diagram is from the factory Spare Parts Catalogue, which is a useful document to have. You can download a PDF of it, as well as several others, from
https://drive.google.com/drive/fold...yMy00ZDhkLTliOWEtOWU1OWRhNDZhYmRl?usp=sharing
The SPC doesn't always illustrate all the parts (especially production changes), but it at least lists the vast majority of them. I'm slowly trying to add the missing illustrations, but since I'm a lousy artist, it's rough going.