Ulysse Nardin flies under the radar, but in the past, it released lots of watches with the first rate guilloche work. This one is from 1985. What is unusual about this dial is that it is executed in niello technique according to UN: silver or copper surface covered with sulphur paste, fired to oxidize the surface, and then engraved. I never heard of this technique used for dials. The fact that it is a rattrapante doesn’t hurt either.