Not without marring the leather. I wanted to add softening the leather at the seam, stretching it, and quickly gluing it in place might yield desired results, but doubtful.
IMO removing the leather is not a viable option because of the riveted lock. There is no way to remove the lock and replace it with a NOS lock over new leather. You might be satisfied with new leather and not replacing the lock if the top has a super tight fit. That still leaves visible holes in the top from the lock. With all of that you still have to be able to replicate the finished ends with the new leather, another monumental task.
If the seam separation is uniform then gluing a strip of leather in the gap might be your best move, then refinish the leather to mask the inserted strip. Fellinis have a flat land about 1.5" wide on the front and back. You can cut a strip wide enough to make it easier to replace the one separated seam with two new tight seams. Take care to match up the width with the finished ends and their angle cuts for a clean look.
Thanks. Have you ever seen the results of someone trying the technique you describe?