I would do no more than polish it by hand. You do have to use it on your face so I like to know mine are clean enough for that. As for the scales you could leave them or make new ones (save the old) and I would lean towards new. Especially if it doesn't open and close just right. It's hard to use a razor if the edge keeps hitting the scales and ruining the blade/shave. Ultimately in the end, you and the razor will decide how you get along.