Start at the bottom, finish at the top.
IMO it is absolutely necessary to do whatever repairs are necessary on the belly of the beast prior to doing ANYTHING on the inside.
See both of my projects in my signature line.
You will have a much better feel for the rebuild after becoming acquainted with the bottom side.
As stated, axles are mandatory if you want suspension. Check out the warranties offered by torsion axle manufacturers to get a feel for the life of the rubber in similar suspensions. Remember, the torsion axles on an Airstream are full loaded all of the time.
Mineola is not far from Zavalla, drop by the Texas Airstream Harbor and you can inspect at least 50 trailers at any given time.
As recommended by others, study and read as many rebuild threads as you can, get a budget for time and cost, then at least double it.
There are several threads documented that include typical costs of some rebuilds. To do it right is not inexpensive nor for the faint of heart.
PM me (there are others willing to help) for specific questions.
"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.