So, junkyards were a complete bust. Same for some of the larger online used part sellers. Oh well.
But I did find a NEW one on eBay for 158 bucks. As that's a hundred dollars less than any of the US Kia part resellers, that's what I got. It's white, but I've confirmed above I can switch the top painted part with mine. (I cannot tell you how much it pisses me off that a freaking antenna is 250 bucks retail......)
Sadly, the eBay one I found ships from from Korea (some guy selling kia parts I guess), so I won't see it for several weeks.
But.... I can wait (see previous comment, I at least have a temporary antenna in play for now.
Meanwhile, my car's rear will remain unassembled. No way am I putting it all back, only to do the full trim removal a second time. Once is enough hahahahahaha. I did pop the headliner back up, held in place by the two push pins on either side of the rear ceiling light.