I don't see any reason why it could not be. When I got my college ring many many years ago, they mispelled my name on the engraving on hte inside of the ring. I took it back and they sent it back to the company that made it and I got it back in about 10 days or so with the correct engraving.
The problem would be finding someone that would do it for you. Looking for goldsmiths in your area would probably be your best shot. Just remember that most custom reworking on antiques carries no warranty.