I have never dealt with this specific problem (I've altered sporrans from day to formal, though) but I have found similar odd things on amazon and eBay. You may have already considered that but thought I'd mention it. After that, if you live in an area with a Hobby Lobby, or Michael's, or JoAnn's, ask one of the associates for help- they could likely hunt down something that would work, if you describe it to them.