OK, so after much nashing of teeth over Python not emerging, I bit the bullet and wiped my disk :jawdrop:
One reboot and wanging my new stage3 onto my sparc I discovered a few missing files - heh. Most of them were the fault of baselayout not installing system FreeBSD files (bad me) and one was a gcc-config bug where mv/cp is linked against libgcc_s.so as such can't copy libgcc_s.so from the specific gcc lib dir to /lib. Now vapier thinks that things like mv linking against libgcc_s are toolchain bugs: I'm inclined to agree only Gentoo gcc-4.x seems todo this on BSD as gcc-3.4.x doesn't. However, until we can find out why gcc wants todo this, we really need gcc-config fixed. Besides, other archs may have this issue too, so it's not like it's bad or anything ;)
But the really good news is that emerging Python now works :D This means I can make a puka stage 3 using catalyst once Flameeyes emails me the spec files.