That duracoat job is beautiful.
For my speed graphic, I cleaned it up the graflok back (off the camera) with simple green (diluted) scrubbed it gently with a towel, rinsed it off. After drying, I re-greased the springs with spray-on lithium grease. To fix the missing paint, I bought some black brush-on touch up paint for a couple dollars at the autoparts store. I also used the black touchup paint elsewhere on the camera where there were scuffs and dings in the finish. The paint goes on pretty smooth if you don't put it on too slowly.