Rebuilt the shift linkage. There is a particular order all the parts have to go back together, and I got it wrong. Twice! I also had to spend quite a while sanding and re-sanding the first linkage section. It rides in two widely spaced brass sleeves. Apparently, some time in the past, the linkage was forced, resulting in a slight bow to the linkage shaft. Combined with years of rust pitting, it was just enough to cause the assembly to stick. With a little patience, it now moves easily and smoothly again. In addition to cleaning the larger parts, I also rinsed out, and re-packed the u-joints with grease.
Before
After