Listen to this noise...

That clip does not have to be tight, the parts ain't going anywhere. I have run my distributor for hundreds of miles without the clip. Far as I can tell, it's just an assembly-line aid.
What you think is wear, or what looks like wear, is not wear; that is how it is made. When it has oil on it, it is a bearing; it only moves a few degrees.
The nylon parts you found appear to be part of an old point set.