seems like that would work, anyone have a door for a 68 ?Just thought of something.
Make your own using an old console lid and some rubber cup holders from some place or metal ones? i would use rubber or rubber lined to keep vibration down and make them removable for cleaning. I think you could use a hole saw to cut the holes and just slip the cup holders in depending on what you find. I know late model cars have plenty of removable ones and you might find somethng in the junk yard. For the cost of a console door, cup holders and hole saw your in the game.