Welcome to the forums.
I have a '75 Argosy 28, so I hope I'll be able to help with some of your questions.
Being from around Atlanta, I can never forget, "Where's Snellville?" on the old Maxie Price TV ads. I knew where Snellville was because I lived in Norcross for a time.
My first advice would be
1. Don't junk the air conditioner if it's not working. The Armstrong is industrial grade and your local A/C guy can get parts for it and work on it.
2. If you have the rear bath, think about putting a shut-off valve in the line going to the toilet. It can have a failure mode that floods the rear of the trailer.
3. If you have a front gaucho/fresh water tank, look carefully for cracks in the water fill. These can lead to bad floor rot underneath.
4. The door gasket is a weak point. Check the plywood under the door for integrity, and make sure your gasket is good.
5. If the fridge hasn't been plugged in, expect a failure of the electric heating unit shortly after you start using the trailer. That's happened to me twice now.
6. Check the floor around the wheelwells. My Argosy has some rot there between the battery compartment and the plastic wheelwell liner.
7. Check the propane tanks to make sure that you have the new, mandated safety valves on them.
And enjoy this new to you travel trailer.
1975 Argosy 28 "Argosy"
1979 Excella 500 31 "Betsy"
1992 Lincoln Mk 7 LSC
2003 Dodge 2500 Cummins "TowHog"
"Lucy Loosehair" the cat - Airstream mascot
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