72 Duster with a Rusty fuel system....how do I avoid this???

Like many of you, I have a series of project cars here that are in various stages of completion. One of the cars belongs to my Brother in law. The project started in 2007. It only needs interior work now but since the BIL lives out of state, I am storing the car in my shop.
In 2007 we replaced the gas tank with a reasonably clean used one. In the years since, the car has only been driven on the road once along with being driven in and out of the shop each time I prime or paint another car. The carburetor has been contaminated a few times from crappy fuel even with a Fram filter in between the pump and the carburetor. I do intend to replace the tank and sending unit eventually but until then, what can be done to avoid fuel contamination? Will a full tank develop less rust than a tank with only a few gallons in it?
I probably should run the carb dry when I expect to let it sit for awhile.