It's great that you're trying to help these birds, they sure need it. But you've set yourself up for the long haul.
Most respiratory type illnesses stay in the birds for life, and when they are seemingly healthy, they're still carriers. You can't ever put them with your current flock unless you get a true diagnosis of what they have from a vet. There actually isn't a chicken "cold"... everything is far more serious than that. You can't sell them or give them away, you'll be sending along the illness too.
Once those diseases land in a location, unless they cull the entire flock and start over, there will always be a bird showing symptoms. Many will die without treatment, but some will survive and remain carriers, or relapse themselves into it during stressful times.
Antibiotics will treat the symptoms while the virus runs it's course, if it's a viral type. Could be bacterial. Could be viral.
Wouldn't be a bad idea to give them electrolytes, and put them on a high protein game bird feed with oyster shell separate. Lot's of healthy greens too, and grit scattered around.
If you're going to do chicken rescue, it would be best if you could have a separate coop for them, well away from your healthy layers. Put a quarantine area near the rescue coop, in case you bring in more.
You need to be very careful with biosecurity. Washing hands between visits from one group to another, plastic bags over your shoes that you can remove. Sanitizing feeders and waterers, etc.
The one with the bad eye may need lanced, have you looked at it closely? You may need an antibiotic eye cream, and daily cleaning. If it goes on too long vision will be lost in that eye.
A turkey poult will not have a comb at all. It will have a fuzzy little snood instead, a little thing that pops up off the forehead. It will also have a much shorter beak than a chicken. Baby turkeys are really cute in the face! If you really do have a turkey, it will need a special high protein feed, 26% is best, but most are 24%. Wouldn't hurt to have the rescue hens on that same feed while they grow feathers.
Animal control may not be able to do anything. If there is food, water, and shelter, there's nothing they can do. Chickens in molt or roughed up by a rooster just look generally terrible. Not sure if they'll do anything about mites and broken legs. I've seen some pretty terrible chicken places, bald birds and severe over crowding. Nothing animal control would do.
If one of the birds passes away, it would be wise to send it for a necroscopy, that way you can know what the other birds remaining may have. You should be able to find an AG extension office that can point you in the right direction. Start with a vet school if you have one nearby.
