Help!!! Chicken with red underbelly/breast and no feathers

[QuacMoldy]

We have owned chickens for 4ish years. The first ones we got from my husband's mom, already in their laying years, though not sure how old any of them were. From there we have hatched out a few clutches of varying size and also bought some chickens. We have had few health problems until this year.
Now this year we have encountered impacted crop and sour crop as well as egg bound hens and bumblefoot.
And just tonight I found a chicken who's pictures I will attach pictures of. Her comb and waddle are a healthy vibrant red but she had a hard inflamed area or growth on the right side of her abdomen back towards her tail and her skin is very red with no feathers only where it's very red. Relevant or not, there is also a small area towards the top of the picture on her breast bone that looks like it's been scraped but has healed and it's kind of white like chickens skin usually looks. She acts pretty normal, but the growth/inflammation is what has me worried. Combined with the redness, makes me think infection.
Our chickens are mostly free-range, but have a coop and run we can lock them in if we need to be away for an extended time or need to remind them where to lay their eggs
I hope someone knows what I'm looking at because I don't. I've seen molting before and this doesn't put me in mind of it.
Thanks alot, chicken friends!

 

[Wyorp Rock]

Give her a dusting for mites and lice with some Permethrin.

The yellowish scab on her keel is mild breast blister which can be common. A hen rests on that spot while roosting and over time pressure from roosting can cause a blister. See that your roosting bars are wide enough or not too rough.