I have seen a Mac Amp that was repaired around the headphone jack by somehow applying black paint to the back side of the face plate. I don't know for sure how it was done but my guess is that you would have to remove the faceplate then my apply black paint from the rear side. The repair was barely noticeable unless if you looked real close, but it looked a lot better that the bubble. Perhaps some knows more about this technique, since I own a few Mac pieces I would like to know for sure how it was done.
