A couple of dry scales is no big deal...I can't really see up close but the scales dont look lifted or injured that i can see. My hens legs look crusty but i feel thats normal. If the scales lift up it would be definite sign of scaly legmites. You can Google images of chickens with it. They seem more puffy in my opinion. You could always oil their legs if you are super worried. I dont think it will bother them if they dont have it.
But crusty legs is NOT normal!
