GM used the same type of clips for a lot of years to hold parts of the interior trim in, try pulling some of the snap in interior panels off a late 90s GM car next time you're at the yard, you might get lucky and find something that will work for you.
Winner, winner!!
Chicken dinner!!
I tried the Jeep dealer and struck out, as expected.
GrimmJeeper's comment reminded me that I had indeed seen similar fasteners in my truck (an '02 Silverado). I couldn't recall exactly where, but it didn't take long to find them. Here they are on the access panel for the fuses (driver's side, end of dash):
Not quite identical, but promising. A couple of nice features are that they appear to be plated and they have little prongs to keep them in place.
I didn't have time for a trip to the junkyard, but the Chevy stealership isn't too far from home. I was able to actually purchase just the clips. No need to purchase an entire dash assembly to get them. These particular clips are P/N 11588650. They aren't exactly cheap at $6 each, but $24 to solve this problem is a reasonable value. That, and the dollar ain't what it used to be. These ones might even have better plating than the ones on my truck:
Installation on the shroud for the electric fan was no problem at all:
For the mechanical fan, a bit of a modification is required. The tabs for the mechanical fan have a pair of ridges which interfere:
I tried putting the clips on, and they will indeed go on the shroud if you position them to one side:
However, if you try the clips that way, they won't fit in the slots in the support. The problem is that the extra material (the ridge) makes them too thick to fit in the slot. Rather than modify the support to take a thicker clip I chose to remove the ridges. A few minutes with a couple of files and I had the tabs down to a plain surface:
Now everything fits, and hopefully these clips will not get lost as the factory ones did.
One last bit of advice: Do not hand a pair of these clips to your junior assistant. Particularly if your junior assistant is of the inquisitive sort. Yes, the clips will nest together neatly. And no, they will not come back apart nicely.
Those prongs which work to keep the clips from escaping their task also do a wonderful job of holding them together when joined as above. You can only free up one side at a time. The other side will have the prongs well wedged into its mate. I used a piece of metal strapping to get one side locked out while I then worked on the other side. Little varmint.