This is the Tamiya Initial (africa) to which I'm adding the voyager PE fenders. I used the kit part to get a "line" on where the tops of the fenders should be but it doesn't look quite right to me...

The front half is not perfectly parallel to the bottom of the sponson per Dave's drawing:

I'm not sure if I should lower the rear line a bit and then correct the angle for the front half, or if I should simply correct the front half using the existing rear line as a starting place (I think if I do the later, the front most fender will be too high).