Believe you're right, unfortunately. The problem with used is it's replacing a worn axle with another worn axle, and maybe less wear...but still worn. Jim Carter's says they don't have any but gave the name and number of a Tom Myers in OK, who I haven't called yet. Nor have I posted yet in our parts wanted forum.
May go ahead and put it back together and just run it until I find a suitable axle shaft, since it's not much trouble to change an individual axle. I'm currently changing out the complete 4.11 gears/driveshaft assembly to the 3.55 (I have both complete assemblies) that should work better with the new rebuilt 235 than it did with the 216.