Is this a 60-61 only part or???

[Corts60]

SO I was just going through the "Let's see your suburban" thread and I noticed that almost no one has the trim panel between their back quarter windows like the one I have. It is a metal piece that covers the vertical center bar in the side windows.
This is what I am talking about:

In this pic my 'burb is parked next to this '61 Chevy and it also does not have the trim plate.

The only other one I saw that had them was KIC's suburban but his is also a '60 GMC so I'm wondering if anyone has a 60-61 Chevy that can confirm it was used on both makes. Also, if anyone has a 62+ suburban that has them let's see them.

I'm guessing these are pretty rare then if they are only used on 60-61's.