Now that sounds like fun, Andy.
I got bit by the FAL aftermarket bug. I asked Ed if his free-float tubes will work with a fch. He said he's never had anyone ask him to do it, and he acted like it wouldn't work, no room for it. That's a shame because I've grown attached to the fch. His tubes seem to be the strongest true free-floating tubes out there.
I found the Vltor CASV-FAL and they claim it to be free floating, but it mounts in both front and back, so I don't see how that's free floating. It looks like it might work with a fch, but I'm not positive it will and I haven't been able to find any pics online of one mounted to a rifle outfitted with a fch. In any case the Vltor is $300. I imagine Ed's would be about the same after installation. I need to decide how I'm going to proceed. I might have to ditch the fch.
You FAL purists are going to hate me when I'm done.