#1 Airstream doesn't design or manufacture air conditioners, or any of the appliances, or heaters. Airstream uses the same equipment as all other RVs.
#2 The black paint is a bit of concern. The black paint on the front could be a cosmetic preference of a previous owner. OR , it could be to protect the front from road rocks, OR it could be to cover up peeling clear coat.
BUTů.There is a better chance that the paint is to cover body putty that was used to repair a dent or rip in the front, where damage is common, from jack knifing while backing up, or something big flying up from the road.
Ball park figure for a panel replacement is $1000. Plus stripping and polishing of the panels $$???? You could get the rock guards for the front, that would almost hide the black. ( about ?? $1000 for that too )
If you ended up replacing the front panels, It might be a good idea to get the rock guards as well.
The other option would be to just enjoy the trailer, or buy something else.