... and I fell in love with it at first sight when I viewed it several years ago because of the feature you mention of its domed case back and its dial. I must add that also the blue soleil dial is breathtaking.
The only other watches I know which have a similar caseback which shows its rotor in a similar way are the modern Speedmaster automatic line with two subdials and its 9900 series movement.
Both watches are delight to wear and view at their both sides.
Keep enjoying and loving yours so much!
Best cordial regards, Abel