Re: What are these called and where can I get replacements?
If your library has older Motor's or Mitchell's crash books, you should easily be able to look up the name and part #.
If you know somebody with a body shop, or insurance adjuster, they might be able to find the information on their computerized system.
Last (maybe should be first) but not least, the parts counter at your local Jeep dealer.
Armed with the name and part #, eBay would probably be your best bet. A junkyard might have them, but they may already be aged and dried out.
If you need a shoulder to cry on ...
... pull over to the side of the road!