Axle wobble

["The Staub Family" <jstaub@domain.elided>]

The other night I was following my Scout II and noticed that the right rear
wheel was wobbling quite a bit. It always vibrates about 50-60 mph and
lessens as it goes near 70, so now I know why. I rotated the tire with one
of the front ones, and it did the same thing. So I jacked it up and
measured about 3/16" wobble and marked the location of the high spot on the
tire. Then, I rotated the tire 180 degrees while leaving the axle in the
same position and saw that the high spot was now on the opposite end of the
tire (does that make any sense?), so my problem appears to be in my axle
shaft, not the rim. There is in-out play on the shaft, but no noticeable
side to side movement. I also couldn't find enough crud or rust under the
drum to make a difference. I figured I'd start by trying new bearings
anyway, but the IH manual states that ther are four different types of
wheel ends- unit bearings, adjusting ring, full floating, or tapered axle
shaft- but doesn't say which goes on which models. I don't want to tear it
down until I have the parts to put it back together. Can anyone help ?
Should I even be messing with the bearings, or does it sound like I need a
new shaft? Finally, if the bearings and shaft are fine but the shaft end
plate is not perpindicular to the shaft, can it be shimmed or milled?
Thanks for any advice or suggestions.               John

'79 Scout II, one wobbly wheel, not too shabby otheriwise