If the scratch is not too deep, you might try using Brasso and rubbing with a paper towel. You may need to do this several times before the scratch disappears. Brasso is epecially effective for removing scuffing on the plastic. This has worked for me.
I'd just order up a new housing and throw the radio around. Install the new housing when and if you decide to sell. As soon as I stop babying radios, I get more use out of them.