My rescues were from an abandoned FFA project. They were half-starved and badly dehydrated. Many had severe injuries from pecking and from poor housing. I was only able to save 2 of the 14. I went back to get the rest, and they were gone.
I have 4 I ordered, but the rest are TSC bin "specials"...
My girl was an Australorp. But I see your point. I tend to be of the "Let me take the cast offs so they can be happy for at least a little while" camp.
Luck isn't in it: you were prepared! Nice!
With my girl, I saw what turned out to be lash material, but it didn't look like it at the time. She was one of my rescue hens, and she'd come from deplorable conditions. I thought it was urates from high temps and dehydration. Now that I know better...
Lash material = bad juju. I hope that vet gets back to you. After I lost my Australorp to a reproductive infection, the vet said early antibiotic treatment was just about the only thing that might have saved her.