I have one coming from DPMS, got it from Brownells. I'll let you know if it works without mods. Otherwise I'll be dremelling.
How have you been securing SR25 lowers thus far for disassembly? Lately I've heard some issues with securing lowers via vise blocks to remove castle nuts, but it seems that 98% of everyone still does it like that, and actual reported problems are virtually non-existent.