I don't know if this has been done but I made one using a wallet chain from Hot Topic it was on sale for $2.99 I then got a cheap watch strap for $1.99 from walmart and put the rings in the watch straps if you need to clip it to your sporran just cut it in the center and use the clips that would attach the chain to the leather strap and the one that would be put on the wallet. I think it looke rather nice. I'll get pictures up when I can