Wow -- pretty pricey piece of equipment. I can't think of any alternative, except maybe to post a "parts wanted" ad in the sale forum. It's amazing they don't fail more often since they get tensioned and relaxed in a corrosive environment about 3000 - 3600 times per hour while pedaling. Unfortunately with those, there is no good way to know if or when they might separate.
If the drive is in otherwise solid shape, buying the replacement might be your best alternative. Those "03 drives were really built well though and should last a long time. This might be a good time to look everything over carefully and see what else might be marginal, loose or sloppy. For instance, your SS mast cotter pins should probably be replaced (cheap but very important) since they get worn but you can't really inspect them. If your sprocket shaft is loose, maybe see if the bushings look worn.
