I may be the bearer of bad news. Only from my experience with the '87, I don't think you will be able to fish the wires.
Lots of tight bends through ungrommeted small holes, plus, my wire bundles were tie wrapped at various points.
You may want to do a search on "rebuild" or "interior gutted" with the year added close to your trailer. Several forum members have removed interior walls and have documented the pictures for the benefit of the forum members.
A picture is worth a thousand words when it comes to understanding the interior construction and wiring of these units.
"Suck it up, spend the bucks, do it right the first time."
WBCCI # 1113
Trailer '78 31' Sovereign
Living Large at an Airstream Park on the Largest Lake Totally Contained in Texas
Texas Airstream Harbor, Inc.