I'd go with mild frostbite.Apart from today and yesterday, the temperature was negative from evenings to mornings.
In my locality, we have had -8°C (17,6 °C) three mornings ago... probably -10°C (14°F) at least when it was darker...?
Wattles have pretty much the same pattern of discoloration on both sides, likely from drinking water/getting wattles wet.
Comb discoloration looks to be from contact, maybe to the plastic roofing of housing or just exposure.
I do see a bit of sunken eyes on both sides as well, perhaps he may have had respiratory illness like MG, but if he's not showing signs of any illness now, is eating/drinking, active and acting normal, then I'd just monitor him.
No extra supplements, no treatments, just monitor.