Yes it fits, but I have been told you need the rear subframe also,not keen myself looks very r1 or maybe the r1 looks very 1299.
Here is ebay link, Noticed its missing the seat/centre part ?? Ducati 1299s Panigale Complete Rear End Streetfighter 1199 899 | eBay
You know what I struggle with, it's when people are selling fairly expensive stuff on eBay and yet they show pictures of it lying on concrete or walls etc I mean what honest chance is there it's spotless, more to the point, if it wasn't spotless surely trying not to mark it any further makes more sense?