Hi booberboo: Welcome to the vintage Airstream hobby. These vintage Sovereigns can be renovated into modern travel trailers, and customized to your liking. It is a big project, but not as big a building a house, a boat or an airplane for that matter.
Airstream Forums has a category called Airstream Knowledgebase, then trailers, then Sovereign
and finally your year range. You will find this category near the bottom of the Forums page. You will see many Sovereign
project threads here where you can see how other folks did their projects; the good, the bad and the ugly. Oh well, I call it fun.
I nicely renovated 70s Sovereign may be worth maybe $35k with documentation of the work done. A new Airstream is over $95k of similar size. Materials to renovate can be $15k assuming all new appliances. Time to renovate an old Airstream is likely over 1000 hours. A professional shop could do excellent work, but the end result at $100/hr shop rate would prohibit that approach seems to me. Most vintage Airstream enthusiasts do their own work, for free!
So jump right in. Make a project plan based on the trailer's needs. Then take it one step at a time.
Stay well... Airstreams won't give you covid. Going to the hardware store can.