We've only had chickens for about 18 months, but we've had several different groups of them. We still have some of the original chickens, which were 10 months old when we got them. I'm not sure what a normal molt looks like. Such as, is losing a bunch of feathers to the point of lots of bare skin is normal for a molt or not? Some of our chickens have molted, seen by stopping laying eggs and they look ruffled and scruffy for a while, but we've not had any chickens with bare skin.
Perhaps they could also be picking each other's feathers? I hear this is common if they aren't getting enough protein because feathers are high in protein.
In any case, it sounds like they were perhaps not getting enough to eat and it sounds like a good move to get them a feeder and have it filled with feed.
If they are caged and not allowed to roam freely outdoors, also be sure to supply them with grit...fine gravel they eat that is necessary for them to properly digest food since they don't have teeth to chew with. Grit is not commonly mixed with feed, so you need to offer it in a small container on the side...they will eat as much as they need. Your feed store should have some.
The creators of BackYard Chickens also have written a pretty decent book called "Raising Chickens for Dummies". Much of the info that is in the book can be gleaned online, but it can be useful to have it all in one place.
