Replacing Armstrong AC with modern -- need service near Upstate South Carolina

[EngiDent]

Hi
1967 Overlander Land Yacht
Has original Armstrong AC. Still works, but condenser fins are badly corroded. I have a good set of condensers in a junked unit, and I have plenty of R22, but I work all the time and I'm tired of wiring / capacitor emergencies and inability to keep up with summer heat in SC. I'm pulling the plug and having "the hole" cut in the roof.
I do not trust anyone in my hometown of Spartanburg SC. They are all disreputable. Where can I go within a couple hours of here to do find someone experienced with vintage Airstreams, bracing the roof, dealing with aluminum wiring etc??
Thanks y'all
Dave