New and rare timepiece - congrats.
But what I do not understand, what's about the word "pano"?

From my point of view Pano might be the short cut for the so-called Panoramadatum.
Therefore there a models like Pano-Reserve, Pano-Lunar, Pano-Matic. All these models have this large date. But, what about the name "pano-invers"? there is no date.

Nevertheless... a fine watch, indeed!