your chick picture looks like you have a couple silvers and a couple of what I called brown/red, but the older pictures dont.
they look like mixed chicks?,
A couple look like the brown/gold that some folks have been working on, not a recognized color yet, but a work in progress.
the one with the black striped feathers does look like a cockerl, but can\'t tell much from a photo, but our cockerls seemd to always be way behing in feathering from the pullets.
at the age you have pictured, you can easily tell a cockerl, as their \"saddle\" feathers are beginning to come in, just lift the feathers on the back, towards the tail region, and look along their back, if you see pointy feathers coming in it is a cockerl, a pullet\'s feathers are blunt and rounded.
It is good to look at the bottoms of their feet too, I see \"willow\" peeking between the toes on some, those most like;ly have yellow or willow foot pads, instead of white ones. My own stock origionated from hatchery stock, and even though we made lots of improvements with them, that willow/yellow still was cropping up even 7 generations in..so it is not an easy trait to breed out..my best recomendation it to try to avoind using ones with willow leggs and /or foot pads in your breeding project.