For a start you can change colors in MFCG to those in VG. The result will look worse than any preset, but it will save you some recoloring. MFCG's style is intentionally flat, so you'll need to add some 3D effects. Here are tutorials how to create shaded roofs and "realistic" ground shadows. It's very easy to make water look like on village maps, but there are no trees on city maps, so you'll have just to draw them.
Instead of repainting an exported PNG, you can try to export a map as JSON and import it to City Viewer. A top-down view will give you something already close enough to what you probably need:
