I just used straight gumpaste and shaped the links individually. As I made each one I hooked it onto the next one. Good gumpaste dries really fast, so as I was going along making the chain I would occasionally move each ring to make sure they were not sticking together. It helps to have a picture of a real purse in front of you for reference.
After the chain is completely dry you can paint it with gold luster dust thinned with vodka so the chain looks like real metal. Again, move the links as they are drying to make sure they are not all sticking together.
Once the chain is complete you can make the fondant handles and buckles to fit right onto the chain.