Without seeing it in person, cannot advise. At only 10', I might be inclined to simply replace it.
If the rust is severe, it's time to relegate it to a non-critical role, like hanging steel plates.
Chains are useful tools but not all chains are equal, even when the links appear to be the same size. There are chains made with high strength steel and there are cheap chains that appear to be identical at first glance. When they're old and discolored, they pretty much all look the same. Knowing the original quality is important.
For emergency recovery I keep a nylon tow strap in my truck. They are lighter than chains, they don't rust and store easily. In terms of weight verses strength, they are far better. Keep them out of direct sunlight and they last a long time.