I've also noticed that Federal cases, ESPECIALLY the ones with the balls as you've pictured, are trimmed shorter than the typical 1.750" from the factory. When I was trimming a load of mixed cases, those were the only ones my trimmer would regularly not touch. For that reason (i.e. inconsistent neck tension) I tend to avoid them as well.
I'm looking for CZ grips, but if you guys are going to put together an order, I'd love to get in on it too. How would that work exactly? One person would receive everyone's grips and then re-ship them out?