I've tracked down all of the emblems to spell out OLDSMOBILE in the grill of my 1957 Olds. However, I can't seem to find a retainer clip/nut that fits to hold them on. Does anyone know of a place that sells them? They look like this:

 

I'll bet the right sized speed nut will work. Not sure how concerned you are with originality.

Check out AMK products' website WWW.AMKPRODUCTS.COM
Mcmaster Carr is another source.www.mcmaster.com

 

Thanks. I will take a look at these places.