Is this goof going to cause problems?

[incoma]

I finally got my vent glass installed in my frame...(not very tough with the right gasket) and screwed up the install. I was so giddy to have gotten the glass mounted in the frame that I continued "fast forward" to install the frame and rivet the sucker into the main frame.

Problem is that I forgot to install this "pivot stop"... I don't want to drill out the pop rivet, because I don't want to buy another kit. Will it hurt anything to not have the "pivot stop" installed?

I'm referring to the washer looking thing that's got one rounded side and one square side. I've highlighted it in yellow and put an arrow in where it should be installed.

I looked at the other side and it doesn't seem to do a whole lot... am I missing something?