Checking a spark plug and the distributor

I wanted to check a few things in the ignition system today, mainly the spark plugs and the distributor.

Actually I was thinking of just replacing all 8 spark plugs but getting the easiets one out was already such a pain in the ass that I just put it back and left the other 7 alone.

So I now know that there are ACDelco plugs in it and that the one I took out seems OK. Well, I think.

OK, yes?

Then I had a look in the distributor. I didn't know exactly how it works but when I found out I was pretty perplexed. So the blue thingy in the picture below just shaves against the copper contacts here? Really?

Not sure if this looks OK or not...