having worked on alot of antiques.. i have alot of experience in removing stuck steering wheels.
once all the easy and medium non destructive stuff fails. ie.. penetrant oil, pullers, tapping onthe hub, etc, the next thing to do is locate a new or used steering wheel. once you locate one, then you can move up into the heavy and destructive removal methods, including heating the hub with a torch.. also, using 2 hammers to beat on the hub side to side to enlarge it's id... use one hammer 180' over as a backup.. that protects the steering column and wormshaft.
if that fails, what I usually do is cut the spokes and rim off with a grinder, then make some top to bottom cuts in the hub with a die grinder / cutoff wheel or angle grinder.. 1 can work, but 2 is better.. even 3 on super rusty things. cut 95% thru the hub.. stay out of the wormshaft... then in many cases, the heat of grinding and themetal removal lets the hub loosen up after hitting with more penetrant oil.. can sometimes use a mild puller on them.. other times you have to go ahead and use a fat cold chissle wedged into the cuts you made to go ahead and split the hub the rest of the way off..
clean up and splines or threads ont he wormshaft with a pick, thread repair file, and / or triangular file, apply never seize liberally when done, and repalce steering wheel..
that 'floorplan' has yet to fail to remove even the most stubborn rusted on non oem/oem steering wheel on any tractor I've ever owned... and I've never ruined a steering wormshaft doing it that way either..
soundguy