First of all let me say I'm not sure my ideas are indeed correct.
I've heard three things: The GP opera movement is made inhouse, the Ghengis Kahn is developed in UN's very own development office and is thus inhouse and C. Claret is responsible for both movements. Looking at the pictures below I can conclude that the movements of the UN and GP are indeed one and the same (With some little design differences, especially in the front tourbillon bridge). So, not all of the statements mentioned above can be true. For me the most believable is the third option. C. Claret is used to the fact that he isn't very often creditted for his own work. So he can probably live with the fact that both companies UN and GP imply the watches are developed in their own studios. If GP would make the movement themselves I think they could not live with the fact that UN takes the credit. From all the three bridge tourbillon watches from other companies than GP it's known they bought the ebauche from GP. Futhermore I can believe GP is capable of making those tourbillon watches for third parties as well. But the Opera is far more complicated, so it seems unbelievable to me they also share this movement with third parties.
However the truth might lie in the middle. I'm aware the three bridge tourbillon is inhouse. So the explanation that only the repeater works (and automatons for the UN) are made by claret seems credible. However the UN tourbillon does not look like the three bridge versions at all, in my eyes. So it would mean GP makes the tourbillon ebauche and claret adds the other complication, but for the UN it also changes the tourbillon design. Or if GP indeed makes the complete movement, UN changes the tourbillon. Both options seem uncredible to me. So i still believe C. Claret is 99% responsible for both movements.
Again I'm not sure, actually i'm guessing. I also hope i wrote a little bit understandeble post
regards,
Joram
1)UN movement 2) UN tourbillon 3) GP movement