Thank you for your comments friends. Regarding the air intakes, I was unsure how to paint them as those intakes would absorb much heat from the exhaust and it seems they would rust the same way. Are there any photographic reference on this subject?
The tracks are indeed the vinyl ones from the box, I pinned them to get the notorious sag but the strain on them was so high that they snapped in four different places. Sewing thread and needle was used to repair them along with the drop of super glue. Those stitches remain hidden behind the shurtzen