Sorry to hear about the situation.
I had a similar situation in '92 while traveling in Central America in a Toyota pickup. We broke a leaf spring and rigged the suspension to get us back to the pavement. We then found a local shop that "custom" made our broken part. Since he didn't have the correct leaf to install, he found a compatible (albeit more heavy-duty) leaf. Cut in down, and installed it in several hours (he even "beefed" up the non-broken side with a similar leaf, to keep it balanced).
If you can't find a replacement, ask the automotive or welding shops in the nearest town if they can help.