I just bought a 1975 31' International Sovereign
. The trailer has been sitting in a pasture in eastern San Diego County for 20 years. I do not have floor rot or the "dreaded tail end sag" but there is a 20 year accumulation of dirt, mouse turds, fabric , foam and plastic rot, window and skin oxidation.
I wont be doing a frame off - any time soon - but I will be updating systems and electrics making component and material's improvements where I can.
The information you are posting is both a help and an inspiration. Thank you for taking the time to do it.
Las Vegas NV