Mine broke and I used waxed thread that I had left over from from repairing a split seam on my brogans. It answered very well. I got the thread from a craft store (in the leatherworking section) so you may try that if there's one close to your location.
Pvt., 49th Indiana
"You say that it is your custom to burn widows. Very well. We also have a custom: when men burn a woman alive, we tie a rope around their necks and we hang them. Build your funeral pyre; [then] beside it, my carpenters will build a gallows. You may follow your custom. And then we will follow ours." - General Sir James Napier