I doubt that will work since the oil base poly has a yellow tint to begin with. In addition, there is something in (or not in) the oil base poly that sunlight affects and causes it to yellow even more.

Removing it is the only way, and I feel that is more trouble than it is worth. Look at it this way, you have had a learning experience that didn't hurt you and wasn't too expensive. My learning experiences ALWAYS seem to hurt and ARE expensive.