No that would have been far too easy. I had actually cut the river shapes out of three different layers and hadn't saved versions of those layers without the cut-out rivers. I basically had to do surgery by filling in the cut-outs with copied section of a jpeg I had that combined all the rivers. It took ages, but man I learned a lesson. After much experimenting with eroded heightfields in Wilbur I went back to Inkscape and redrew the rivers.
I used the blurred river technique you once showed me to make a bump map mimicking the depressions that the rivers run through. I added a bit of noise after the blur to give it a slightly rougher look.
Torq