Been there! Haven't lost one yet. I've even tried gluing the grommets in. Didn't work.
Are there any grommets like that locally? Ace? Home Depot? Menards?
I purchased a grommet selection in a nice plastic box from H/F. I had 3 that were close-but alas and alack-NOT close enough.

I looked the up at H D L-the 2 different sizes needed are around $2.60 each.

Not bad AND a hell of a lot cheaper than replacing side covers. And yet again MarkT I am beholdin to ya.

The wire tie is a durn good idea.

I WILL be using that.

You also told me about the strap to hold the wheel in place on reassembly after the spline lube. RIDE SAFE.