If he is still in business he is in your neck of the woods and has done some excellent work in the past. Not sure of the state of his business today but he has been considered a motor GURU when it comes to modifying motors. He has replaced many shafts and made single shafts for dual motors many times for racers and others. You may want to call and if possible go over to his place of business and see what he can do for you. I am sure it would be a piece of cake for him. Time wise, no telling.
Well, Im guessing email will have to do for now. Here is his contact page.