You're very welcome.
On the applesauce, if you make your own, the pectin is in the apple already. That should be fine as long as you just make sure to grind it up into a very fine applesauce consistency so that the gizzard doesn't have to work hard.
You mentioned a small amount of feather loss around the vent, but not a bald one - that's good, as is "no leakage". The pointy areas near the vent are likely the pubic bones to either side. Good on no inflammation or anything else marked abotu the vent.
On the lower abdomen, I mean pretty much under her vent to between her legs. Does she feel like she's holding any fluid, eggs, or anything else there. The thin-ness is what I expected - wanted to make sure.
The diet sounds good and normal. I wonder what her diet was before.. The organic layer, it's completely fortified (including vitamins) correct? I'm not sure what labeling policies are there.
Silly hens - ours stand in the rain, too. The turkeys are the worst at it. Everything else there sounds normal. I'm wondering what about the transition from her previous home to yours triggered it, for surely it did.
The problem might have been building up before and just was triggered with the stress of the move, change of diet, etc.
I suspect that the moldy pellets might have been the initial cause. I was looking for this sort of clue. We have the same type of climate here in Texas - very humid - and it only takes a pellet being down for a bit for mildew to happen. She probably just naturally also picked up more of that while free ranging; scratching under leaves, etc. We should definitely focus on this as one issue and correct it for her.
And as far as the dust goes, ours gets dusty at the bottom, too. Usually I try to tell by smell and looking at the bag. The food should smell strongly of fresh ingredients, not terribly dusty. The bag should look good and new - so wrinkling from humidity, no watermarks, no beetle bore holes, etc.
And my chickens drink from the most horrible puddles of water... no matter what clean water we give (at least the turkeys like the clean water better).
I think there's more to this than simply mycotoxins from mildew and fungus in her system. But that's definitely a factor as it causes neurological symptoms, paralysis, ataxia, etc etc. It also causes deficiencies of oil vitamins which leave the bird more susceptible to other issues. The inflammation of the digestive tract cause the bird to not absorb usual nutrients, and the bombarding of the digestive tract with the pathogenic fungi causes the normal healthy yeast cells (which produce B vitamins, without which 'wry neck' symptoms can happen) to die off.
I definitely would still recommend treating heavily with probiotics and OACV, the oil vitamins (which we'll have to figure out how you can do that there - I'm wondering if you don't have a baby-vitamin in a liquid/oil form there similar to polyvisol here) to replenish that which is short, etc.
Were you doing B vitamin supplementation?
Ohhh an Appenzeller! That's hysterical - I've never seen a picture of anyone's private stock. She's very cute! They're all quite lovely!
I'm glad we can try to help.