Basically it's a 401 in a different body. The controls are the same and it has the same built in cams, based on comparison of the owners manuals.
The top lid just snaps on and off so unless somethings broken or bent it shouldn't be a problem to replace it.
The face plate, well I don't know anything about that part ... yet. I wonder if the 401 shares the same type of hinge system with the 500?
Joe