Welcome ! I've got a 1975 Argosy 26' that we got last fall, and we are about 20% done renovating it :-) We've got the interior out, interior panels out, and insulation removed. I'll be working on dropping the pan today.
Since I'm still a novice, I don't have tons of information to share yet, but I can tell you that I've found the rivet remover tool from Vintage Trailer supply to be super useful for removing the pop rivets in the interior:
Rivet Removal Tool
Also, this site is a wealth of information, and people are great about answering your questions, so post away!
We've got a family Bog at 5goforth
where we'll be documenting our restoration and adventures.
I'll be posting more restoration entries on the blog, and here as the work progresses.
Good luck and happy renovating !