So Black Boy

2017. Think I got mine in May. Mine is the grained lambskin version. But think was released again later. Can't remember when though. More learned people will arrive soon to give a more concise answer...
 
I can also confirm for the quilted so black boy in the grained lambskin version (with sparks of iridescence in the leather), looks like caviar.

It was released for the 17S season. Here is the code for old medium size: A67086 Y25568 94305. I bought mine in April 2017.

Later it was maybe re-released in calfskin/lambskin variations, but not again in the grained leather with caviar look.
 
Thank you! Mine has the iridescent hardware & I got it in summer 2019 in really good condition. I’ve always believed it to be caviar as the leather is the same as my caviar classic flap, but perhaps not. I’ll check the code!