amanico[JLC Moderator]
400911
Jaeger Lecoultre Master Grande Tradition Perpetual Calendar 8 Days Skeleton Enamel.
Jaeger Lecoultre comes back in 2015, 8 years after the Master 8 Days Perpetual Calendar Skeleton, with another 8 Days Perpetual Calendar Skeleton, but with some differences:
The Case is not the Master, but the Master Grande Tradition, much more elegant.
The work of skeletonisation is more traditional, less modern.
The metal changed: Platinum for the 2007 edition, white gold for the 2015 and 2016 editions.
And, last but not least, Jaeger Lecoultre added a nice blue ( or green, in 2016 ) enamel gulloché ring around the movement.
The Blue and Green Editions, side by side:

And the 2007 Edition, for the comparison.
My perfect version would have been the skeleton of the 2007 Edition, with the case of the 2015 / 2016 Editions.
You?
Best,
Nicolas