Welcome to getting to work on your Mom's Airstream! There are a number of fellow airstream addicts in the area--so you aren't alone!
What you face is pretty variable, depending on what grade of airstream you have (there were different options for wiring, depending on what the original owners were willing to pay) and depending on what's happened over the duration of time since 1962
. For instance, most 1961s had paper covered wire, but ours, which is an "international" model has regular plastic coated stuff (which I suppose was really high end stuff those days). Your wiring may or may not be problematic.
There are different ways to mess with wiring (and plumbing, for that matter) depending on what you face. Like regular construction, you can always fish wire or conduit through the walls. Alternatively, the high maintenance approach is to remove the inner walls by drilling out the rivets.