Awww, I'm so sorry CFL. You did an awesome job trying to save them, but they looked very weak. There's not much more that you could have done. To fluff them up, I would have gotten a soft toothbrush, soaked the bristles in warm water, and then gently scrubbed the chick off. Afterwards, it can be towel dried. You can even dry it with a dry soft toothbrush too. Toothbrushes are wonderful for fluffing chicks up.
I agree with Emma about them both being OEGBs too, TSC almost always has those in. They're pretty common, much more common than the other types mentioned.
I'm sorry you lost them. Rest in peace little babies. I'm sure that they knew you cared about them. They died much more peacefully than they would have in the brooder with the others.