I have had almost the same luck with cream legbars - out of four eggs - 3 were boys, 1 girl. That has happened twice. And the larger hatches have had similar ratios. ALWAYS lots more boys than girls. Right now I have two broody hens - and they each have 5 cream legbar eggs under them. I'll be lucky to get one girl from each broody.
I have a CSA friend who will be processing chickens in the fall. I've asked if I could come and watch/help. I want to learn to do them myself - although I've read from some that it's more trouble than it's worth. I don't know. I just feel bad to keep giving away all these roos - knowing I've raised them but they'll end up on someone else's plate.