You might be better off modeling that part in a CAD program from measurements, rather than going the 3D scan route. If it has to meet high tolerances, you'll need to reverse-engineer the part from the scan anyway. But this part doesn't look that hard to measure, so you could probably save yourself a step. Once you've got a solid model, you can generate a mesh, save it as STL, and send it to any 3D printing service bureau that handles the material you want to print it in, which presumably will be something resistant to immersion in diesel fuel. Look for someone with a machine that uses soluble supports, so you don't have a lot of cleanup on each part.