Two of my Golden Comet hens have died over the last two months. Of the four I have left, two have lost feathers (to the

Hello, I'm Dr. Bob.
I'm sorry to read of your losses and the condition of your remaining hens.
Have you found excessive loose feathers around the area where you keep them?

Okay, thank you.
Judging from the lack of feathers laying around and the distribution of the missing feathers, I suspect that you may have cannibalism going on in your flock. Did the ones that died become bloody around.their vents?

The loss of feathers around their vents and wings may indicate feather picking, a form of cannibalism.
Chickens can develop this bad habit if their diets lack sufficient protein.
I would suggest watching the birds interact for some time to see if the unaffected birds are picking at the ones losing their feathers. In the meantime you can try feeding them some dry cat food, one handful per five chickens daily.
If it is a protein deficiency, this may help, but if the behavior is firmly entrenched, the picking may continue and it may be necessary to identify the offenders and debeak them. One third of the top beak is clipped off, effectively preventing the continuation of the behavior. You can read about how to debeak birds by googling "debeaking".
Debeaking is a controversial procedure and should only be used as a last resort. A product called hen saddles by Hen Savers, available online, are an alternative approach to the problem.
Being sure they get some sunlight is important as well, to assure the proper production of vitamin D which helps promote healthy skin and feathers.
If you should have further questions, please let me know.
Best regards,
Dr. Bob