How old are they now, Adam? Hard to tell from those pics. The best way is head on with this breed, IMO. If the comb is raised, very wide and you start to see the three distinct "pea" ridges, you have a boy. If the center ridge is the only one visible and the combs are still yellowish at several weeks old, probably a pullet. That first one's comb looks fairly flat. Can't really see the other one very well, though. I can post pics of known boys and girls at certain young ages, if you want. Maybe that would help illustrate what I mean.