1. Check the screws at the top of the column that hold the shifter arm. If these are loose, you cannot adjust the bottom linkage to work. 2. When you lift the lever for R - 1 at the bottom there is a yoke that lifts the selector. The shaft has a collar which that yoke lifts. The inside edges build up with iron hard oil/dirt. When that dirt gets wet, the yoke slips out of the collar and thus no R-1. It took me days to figure that out. I soaked that dirt and cleaned the collar, bazinga, all still works.
3. The linkage adjustments are approximate, if all is tight and clean the shift is very forgiving. Best to you.