I need to put on a new roof - original 1991. One roofer suggested I should replace the skylights, the other did not. They are Velux FS 606 and VS 606. The VS is leaking slightly, but the flashing around it looks soft. The wood finish is flaking on both. I am leaning toward putting new skylights in to save a problem down the road. But I don't want to open myself up to more problems either. Any help would be greatly appreciated. Thank you.