My friend Julia found this really cute 1950's party dress - in perfect condition except for missing the zipper pull. Rather than replace the vintage metal zip with a new-fangled nylon one, I crafted a replacement pull from my stash of jewelry-making supplies.
I used a sturdier split ring rather than a single jump ring.
Sometimes repair work is more like engineering than sewing! This is certainly true of costuming as well, what with needs for crafting hidden closures for clothes that need to handle quick costume changes and so on.