If you were able to get the retaining clip (washer with the slot) on without removing the shifter from the side of the column to allow rotating the shift rod, then the end of the rod is sitting too far out and pushing on the bottom of the horn ring.

When properly installed, that retaining clip sits down BELOW the surface of the bore you see in the cast column cap piece making the end of the shift rod just about flush.

Removing the shifter from the side will allow you to slide and rotate the shift rod to a much larger degree. It seems like you may have a third plastic bushing in there or the vestiges of one.

You'll need to be able to rotate the shift rod much further to get the clip slid on from toward the ctr of the column, then rotate it back the other way so that the clip is 'captive' in the bore with the opening toward the ctr. This aspect looks correct in your picture, but it looks too high.

All of this is just barely possible, i.e. tight, but it isn't too hard. The shift lever MUST come off first.