replaceing fuse panel under dashboard of my metal fish boat. factory wireing is in good shape,the add on fish finder, cig liter,marine radio from previous owners all have a fuse at the panel and then an inline fuse also do I need them ? all of these have the same fuse size. the grounding "bus" that is on this panel has factory black wires that go into a wire harness and to dash gauges, is this where the battery ground gets to the ground bus??