Welcome to the forums from Pennsylvania. We hope you enjoy your project as much as we've enjoyed ours. We used our second Airstream for storage for a couple of years before we started restoration this spring. So, I agree your first step is to remove all the stored material and assess what you have. You should expect to see some rodent and insect debris and possibly damage, but that fades quickly as you get going on the project. Gas appliances seem to attract both types of critters. We had a mild shock issue on our first trailer that we tracked down to the outside receptacle.
We've found the folks here on the forum very helpful when questions arise. Someone here has been there before and is willing to offer advice and sometimes what "didn't" work for them.
Good luck and please post some photos as you progress. If interested our most recent project is discussed at; http://www.airforums.com/forums/f394...er-155180.html
Many of the ideas came from reading the forums.
Roy and Marie