The expander pin will not work in this case because immediately next to the bushing is the bushing on the end of the arm seen in the photo. That bushing has a grease fitting and has been kept lubricated over its 17 year life and does not have any appreciable wear, so the pin is passing through two bushings, one worn and one unworn.
I did not think about welding the pin to the bushing but, now that you brought it up, I might just do that. The truck is nearing the end of its life and I don't expect ever having to remove the pin again.