Hi, I'm not sure about the bag at all, maybe show pictures of the interior, labels and base?
The shape of it however I do know as it is used by many high end designers, it is often referred to as a Boston bag (Gucci) or Speedy (LV). Loewe use the term bowling bag for some of theirs but the shape is a little different. I haven't seen this shape bag before from Loewe.