Jay, compromise with your conscience--open the right barrel to something like IC and leave the other as is. Best of both worlds. Why continue to handicap yourself--shotgun shells have changed forever. Opening one or both chokes will have zero affect on resale value. As mentioned above by Wilhelm, it's no different than having a stock bent to fit--so it's not "original", but it doesn't change the appearance. Go for it. Just be sure a top smith does the job and polishes the lengthened parallel perfectly (for appearances).

John McCain is my war hero.