Bud,
They're not that hard to find, on the Bay quite often.
I even saw 4 in GM boxes in Portland a few weeks back.
If you're not planning on going to Monroe (Seattle swap meet)you should, you'll never know what you missed!!

By the way it's on the May 15 weekend.
Also on the following weekend in Cloverdale, BC is the Costal swap meet. It's not as large as Monroe but it's one of my favorites. I got 4 NOS 4 clip 15x6 trim rings in the boxes for $50 Canadian a couple of years ago

The swap meet is quirky as it's on Friday afternoon & Saturday only because there's already a junk swap meet there every Sunday.