It's somewhat buggy to find. After meeting the ex-owner, I can never find it.
But after the battle with slavers inside Ebon Hawk, I also not 100% certain to find it. But, after some reload to right before the fight to refight it, I finally found it at the end.
I am not certain what trigger it, though.
(gog version, no content mod other than some skins)
Only storage compartment on Ebon Hawk: GET!